slurm.conf man page

slurm.conf is an ASCII file which describes general Slurm configuration information, the nodes to be managed, information about how those nodes are grouped into partitions, and various scheduling parameters associated with those partitions. This file should be consistent across all nodes in the cluster.

The file location can be modified at system build time using the DEFAULT_SLURM_CONF parameter or at execution time by setting the SLURM_CONF environment variable. The Slurm daemons also allow you to override both the built-in and environment-provided location using the "-f" option on the command line.

The contents of the file are case insensitive except for the names of nodes and partitions. Any text following a "#" in the configuration file is treated as a comment through the end of that line. Changes to the configuration file take effect upon restart of Slurm daemons, daemon receipt of the SIGHUP signal, or execution of the command "scontrol reconfigure" unless otherwise noted.

If a line begins with the word "Include" followed by whitespace and then a file name, that file will be included inline with the current configuration file. For large or complex systems, multiple configuration files may prove easier to manage and enable reuse of some files (See Include Modifiers for more details).

Note on file permissions:

The slurm.conf file must be readable by all users of Slurm, since it is used by many of the Slurm commands. Other files that are defined in the slurm.conf file, such as log files and job accounting files, may need to be created/owned by the user "SlurmUser" to be successfully accessed. Use the "chown" and "chmod" commands to set the ownership and permissions appropriately. See the section File and Directory Permissions for information about the various files and directories used by Slurm.

The name of the backup machine hosting the accounting storage database. If used with the accounting_storage/slurmdbd plugin, this is where the backup slurmdbd would be running. Only used with systems using SlurmDBD, ignored otherwise.

This controls what level of association-based enforcement to impose on job submissions. Valid options are any combination of associations, limits, nojobs, nosteps, qos, safe, and wckeys, or all for all things (expect nojobs and nosteps, they must be requested as well).

If limits, qos, or wckeys are set, associations will automatically be set.

If wckeys is set, TrackWCKey will automatically be set.

If safe is set, limits and associations will automatically be set.

If nojobs is set nosteps will automatically be set.

By enforcing Associations no new job is allowed to run unless a corresponding association exists in the system. If limits are enforced users can be limited by association to whatever job size or run time limits are defined.

If nojobs is set Slurm will not account for any jobs or steps on the system, like wise if nosteps is set Slurm will not account for any steps ran limits will still be enforced.

If safe is enforced a job will only be launched against an association or qos that has a GrpCPUMins limit set if the job will be able to run to completion. Without this option set, jobs will be launched as long as their usage hasn't reached the cpu-minutes limit which can lead to jobs being launched but then killed when the limit is reached.

With qos and/or wckeys enforced jobs will not be scheduled unless a valid qos and/or workload characterization key is specified.

When AccountingStorageEnforce is changed, a restart of the slurmctld daemon is required (not just a "scontrol reconfig").

The password used to gain access to the database to store the accounting data. Only used for database type storage plugins, ignored otherwise. In the case of Slurm DBD (Database Daemon) with MUNGE authentication this can be configured to use a MUNGE daemon specifically configured to provide authentication between clusters while the default MUNGE daemon provides authentication within a cluster. In that case, AccountingStoragePass should specify the named port to be used for communications with the alternate MUNGE daemon (e.g. "/var/run/munge/global.socket.2"). The default value is NULL. Also see DefaultStoragePass.

Comma separated list of resources you wish to track on the cluster. These are the resources requested by the sbatch/srun job when it is submitted. Currently this consists of any GRES, BB (burst buffer) or license along with CPU, Memory, Node, and Energy. By default Billing, CPU, Energy, Memory, and Node are tracked. AccountingStorageTRES=gres/craynetwork,license/iop1 will track billing, cpu, energy, memory, nodes along with a gres called craynetwork as well as a license called iop1. Whenever these resources are used on the cluster they are recorded. The TRES are automatically set up in the database on the start of the slurmctld.

The accounting storage mechanism type. Acceptable values at present include "accounting_storage/filetxt", "accounting_storage/none" and "accounting_storage/slurmdbd". The "accounting_storage/filetxt" value indicates that accounting records will be written to the file specified by the AccountingStorageLoc parameter. The "accounting_storage/slurmdbd" value indicates that accounting records will be written to the Slurm DBD, which manages an underlying MySQL database. See "man slurmdbd" for more information. The default value is "accounting_storage/none" and indicates that account records are not maintained. Note: The filetxt plugin records only a limited subset of accounting information and will prevent some sacct options from proper operation. Also see DefaultStorageType.

If set to "YES" then include the job's comment field in the job complete message sent to the Accounting Storage database. The default is "YES". Note the AdminComment is always recorded in the database.

The AcctGather plugins sampling interval for node accounting. For AcctGather plugin values of none, this parameter is ignored. For all other values this parameter is the number of seconds between node accounting samples. For the acct_gather_energy/rapl plugin, set a value less than 300 because the counters may overflow beyond this rate. The default value is zero. This value disables accounting sampling for nodes. Note: The accounting sampling interval for jobs is determined by the value of JobAcctGatherFrequency.

Identifies the plugin to be used for energy consumption accounting. The jobacct_gather plugin and slurmd daemon call this plugin to collect energy consumption data for jobs and nodes. The collection of energy consumption data takes place on node level, hence only in case of exclusive job allocation the energy consumption measurements will reflect the jobs real consumption. In case of node sharing between jobs the reported consumed energy per job (through sstat or sacct) will not reflect the real energy consumed by the jobs.

Identifies the plugin to be used for infiniband network traffic accounting. The plugin is activated only when profiling on hdf5 files is activated and the user asks for network data collection for jobs through --profile=Network (or =All). The collection of network traffic data takes place on node level, hence only in case of exclusive job allocation the collected values will reflect the jobs real traffic. All network traffic data are logged on hdf5 files per job on each node. No storage on the Slurm database takes place.

Configurable values at present are:

acct_gather_infiniband/none

No infiniband network data are collected.

acct_gather_infiniband/ofed

Infiniband network traffic data are collected from the hardware monitoring counters of Infiniband devices through the OFED library.

Identifies the plugin to be used for filesystem traffic accounting. The plugin is activated only when profiling on hdf5 files is activated and the user asks for filesystem data collection for jobs through --profile=Lustre (or =All). The collection of filesystem traffic data takes place on node level, hence only in case of exclusive job allocation the collected values will reflect the jobs real traffic. All filesystem traffic data are logged on hdf5 files per job on each node. No storage on the Slurm database takes place.

Configurable values at present are:

acct_gather_filesystem/none

No filesystem data are collected.

acct_gather_filesystem/lustre

Lustre filesystem traffic data are collected from the counters found in /proc/fs/lustre/.

Identifies the plugin to be used for detailed job profiling. The jobacct_gather plugin and slurmd daemon call this plugin to collect detailed data such as I/O counts, memory usage, or energy consumption for jobs and nodes. There are interfaces in this plugin to collect data as step start and completion, task start and completion, and at the account gather frequency. The data collected at the node level is related to jobs only in case of exclusive job allocation.

Configurable values at present are:

acct_gather_profile/none

No profile data is collected.

acct_gather_profile/hdf5

This enables the HDF5 plugin. The directory where the profile files are stored and which values are collected are configured in the acct_gather.conf file.

If set to 1, Slurm allows individual jobs to override node's configured CoreSpecCount value. For a job to take advantage of this feature, a command line option of --core-spec must be specified. The default value for this option is 1 for Cray systems and 0 for other system types.

Additional information to be used for authentication of communications between the Slurm daemons (slurmctld and slurmd) and the Slurm clients. The interpretation of this option is specific to the configured AuthType. Multiple options may be specified in a comma delimited list. If not specified, the default authentication information will be used.

cred_expire

Default job step credential lifetime, in seconds (e.g. "cred_expire=1200"). It must be sufficiently long enough to load user environment, run prolog, deal with the slurmd getting paged out of memory, etc. This also controls how long a requeued job must wait before starting again. The default value is 120 seconds.

socket

Path name to a MUNGE daemon socket to use (e.g. "socket=/var/run/munge/munge.socket.2"). The default value is "/var/run/munge/munge.socket.2". Used by auth/munge and crypto/munge.

ttl

Credential lifetime, in seconds (e.g. "ttl=300"). The default value is dependent upon the MUNGE installation, but is typically 300 seconds.

The authentication method for communications between Slurm components. Acceptable values at present include "auth/munge" and "auth/none". The default value is "auth/munge". "auth/none" includes the UID in each communication, but it is not verified. This may be fine for testing purposes, but do not use "auth/none" if you desire any security. "auth/munge" indicates that MUNGE is to be used. (See "https://dun.github.io/munge/" for more information). All Slurm daemons and commands must be terminated prior to changing the value of AuthType and later restarted.

The name that BackupController should be referred to in establishing a communications path. This name will be used as an argument to the gethostbyname() function for identification. For example, "elx0000" might be used to designate the Ethernet address for node "lx0000". By default the BackupAddr will be identical in value to BackupController.

The short, or long, name of the machine where Slurm control functions are to be executed in the event that ControlMachine fails (i.e. the name returned by the command "hostname -s"). This node may also be used as a compute server if so desired. It will come into service as a controller only upon the failure of ControlMachine and will revert to a "standby" mode when the ControlMachine becomes available once again.

The backup controller recovers state information from the StateSaveLocation directory, which must be readable and writable from both the primary and backup controllers. While not essential, it is recommended that you specify a backup controller. See the Relocating Controllers section if you change this.

The maximum time (in seconds) that a batch job is permitted for launching before being considered missing and releasing the allocation. The default value is 10 (seconds). Larger values may be required if more time is required to execute the Prolog, load user environment variables (for Moab spawned jobs), or if the slurmd daemon gets paged from memory.

Note: The test for a job being successfully launched is only performed when the Slurm daemon on the compute node registers state with the slurmctld daemon on the head node, which happens fairly rarely. Therefore a job will not necessarily be terminated if its start time exceeds BatchStartTimeout. This configuration parameter is also applied to launch tasks and avoid aborting srun commands due to long running Prolog scripts.

The system-initiated checkpoint method to be used for user jobs. The slurmctld daemon must be restarted for a change in CheckpointType to take effect. Supported values presently include:

checkpoint/blcr

Berkeley Lab Checkpoint Restart (BLCR). NOTE: If a file is found at sbin/scch (relative to the Slurm installation location), it will be executed upon completion of the checkpoint. This can be a script used for managing the checkpoint files. NOTE: Slurm's BLCR logic only supports batch jobs.

The name by which this Slurm managed cluster is known in the accounting database. This is needed distinguish accounting records when multiple clusters report to the same database. Because of limitations in some databases, any upper case letters in the name will be silently mapped to lower case. In order to avoid confusion, it is recommended that the name be lower case.

The time, in seconds, given for a job to remain in COMPLETING state before any additional jobs are scheduled. If set to zero, pending jobs will be started as soon as possible. Since a COMPLETING job's resources are released for use by other jobs as soon as the Epilog completes on each individual node, this can result in very fragmented resource allocations. To provide jobs with the minimum response time, a value of zero is recommended (no waiting). To minimize fragmentation of resources, a value equal to KillWait plus two is recommended. In that case, setting KillWait to a small value may be beneficial. The default value of CompleteWait is zero seconds. The value may not exceed 65533.

Name that ControlMachine should be referred to in establishing a communications path. This name will be used as an argument to the gethostbyname() function for identification. For example, "elx0000" might be used to designate the Ethernet address for node "lx0000". By default the ControlAddr will be identical in value to ControlMachine.

The short, or long, hostname of the machine where Slurm control functions are executed (i.e. the name returned by the command "hostname -s"). This value must be specified. In order to support some high availability architectures, multiple hostnames may be listed with comma separators and one ControlAddr must be specified. The high availability system must ensure that the slurmctld daemon is running on only one of these hosts at a time. See the Relocating Controllers section if you change this.

The cryptographic signature tool to be used in the creation of job step credentials. The slurmctld daemon must be restarted for a change in CryptoType to take effect. Acceptable values at present include "crypto/munge" and "crypto/openssl". The default value is "crypto/munge" and is the recommended.

Defines specific subsystems which should provide more detailed event logging. Multiple subsystems can be specified with comma separators. Most DebugFlags will result in verbose logging for the identified subsystems and could impact performance. The below DB_* flags are only useful when writing directly to the database. If using the DBD put these debug flags in the slurmdbd.conf. Valid subsystems available today (with more to come) include:

Backfill

Backfill scheduler details

BackfillMap

Backfill scheduler to log a very verbose map of reserved resources through time. Combine with Backfill for a verbose and complete view of the backfill scheduler's work.

BGBlockAlgo

BlueGene block selection details

BGBlockAlgoDeep

BlueGene block selection, more details

BGBlockPick

BlueGene block selection for jobs

BGBlockWires

BlueGene block wiring (switch state details)

BurstBuffer

Burst Buffer plugin

CPU_Bind

CPU binding details for jobs and steps

CpuFrequency

Cpu frequency details for jobs and steps using the --cpu-freq option.

DB_ASSOC

SQL statements/queries when dealing with associations in the database.

DB_EVENT

SQL statements/queries when dealing with (node) events in the database.

DB_JOB

SQL statements/queries when dealing with jobs in the database.

DB_QOS

SQL statements/queries when dealing with QOS in the database.

DB_QUERY

SQL statements/queries when dealing with transactions and such in the database.

DB_RESERVATION

SQL statements/queries when dealing with reservations in the database.

DB_RESOURCE

SQL statements/queries when dealing with resources like licenses in the database.

DB_STEP

SQL statements/queries when dealing with steps in the database.

DB_USAGE

SQL statements/queries when dealing with usage queries and inserts in the database.

Default real memory size available per allocated CPU in megabytes. Used to avoid over-subscribing memory and causing paging. DefMemPerCPU would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). The default value is 0 (unlimited). Also see DefMemPerNode and MaxMemPerCPU. DefMemPerCPU and DefMemPerNode are mutually exclusive.

NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

Default real memory size available per allocated node in megabytes. Used to avoid over-subscribing memory and causing paging. DefMemPerNode would generally be used if whole nodes are allocated to jobs (SelectType=select/linear) and resources are over-subscribed (OverSubscribe=yes or OverSubscribe=force). The default value is 0 (unlimited). Also see DefMemPerCPU and MaxMemPerNode. DefMemPerCPU and DefMemPerNode are mutually exclusive.

NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

The default name of the machine hosting the accounting storage and job completion databases. Only used for database type storage plugins and when the AccountingStorageHost and JobCompHost have not been defined.

The password used to gain access to the database to store the accounting and job completion data. Only used for database type storage plugins, ignored otherwise. Also see AccountingStoragePass and JobCompPass.

The accounting and job completion storage mechanism type. Acceptable values at present include "filetxt", "mysql" and "none". The value "filetxt" indicates that records will be written to a file. The value "mysql" indicates that accounting records will be written to a MySQL or MariaDB database. The default value is "none", which means that records are not maintained. Also see AccountingStorageType and JobCompType.

The number of seconds srun waits for slurmstepd to close the TCP/IP connection used to relay data between the user application and srun when the user application terminates. The default value is 60 seconds. May not exceed 65533.

If set to "ALL" then jobs which exceed a partition's size and/or time limits will be rejected at submission time. If job is submitted to multiple partitions, the job must satisfy the limits on all the requested partitions. If set to "NO" then the job will be accepted and remain queued until the partition limits are altered(Time and Node Limits). If set to "ANY" or "YES" a job must satisfy any of the requested partitions to be submitted. The default value is "NO". NOTE: If set, then a job's QOS can not be used to exceed partition limits. NOTE: The partition limits being considered are it's configured MaxMemPerCPU, MaxMemPerNode, MinNodes, MaxNodes, MaxTime, AllocNodes, AllowAccounts, AllowGroups, AllowQOS, and QOS usage threshold.

Fully qualified pathname of a script to execute as user root on every node when a user's job completes (e.g. "/usr/local/slurm/epilog"). A glob pattern (See glob (7)) may also be used to run more than one epilog script (e.g. "/etc/slurm/epilog.d/*"). The Epilog script or scripts may be used to purge files, disable user login, etc. By default there is no epilog. See Prolog and Epilog Scripts for more information.

The number of microseconds that the slurmctld daemon requires to process an epilog completion message from the slurmd daemons. This parameter can be used to prevent a burst of epilog completion messages from being sent at the same time which should help prevent lost messages and improve throughput for large jobs. The default value is 2000 microseconds. For a 1000 node job, this spreads the epilog completion messages out over two seconds.

Fully qualified pathname of a program for the slurmctld to execute upon termination of a job allocation (e.g. "/usr/local/slurm/epilog_controller"). The program executes as SlurmUser, which gives it permission to drain nodes and requeue the job if a failure occurs (See scontrol(1)). Exactly what the program does and how it accomplishes this is completely at the discretion of the system administrator. Information about the job being initiated, it's allocated nodes, etc. are passed to the program using environment variables. See Prolog and Epilog Scripts for more information.

The external sensors plugin sampling interval. If ExtSensorsType=ext_sensors/none, this parameter is ignored. For all other values of ExtSensorsType, this parameter is the number of seconds between external sensors samples for hardware components (nodes, switches, etc.) The default value is zero. This value disables external sensors sampling. Note: This parameter does not affect external sensors data collection for jobs/steps.

Identifies the plugin to be used for external sensors data collection. Slurmctld calls this plugin to collect external sensors data for jobs/steps and hardware components. In case of node sharing between jobs the reported values per job/step (through sstat or sacct) may not be accurate. See also "man ext_sensors.conf".

Dampen the effect of exceeding a user or group's fair share of allocated resources. Higher values will provides greater ability to differentiate between exceeding the fair share at high levels (e.g. a value of 1 results in almost no difference between overconsumption by a factor of 10 and 100, while a value of 5 will result in a significant difference in priority). The default value is 1.

Controls how a node's configuration specifications in slurm.conf are used. If the number of node configuration entries in the configuration file is significantly lower than the number of nodes, setting FastSchedule to 1 will permit much faster scheduling decisions to be made. (The scheduler can just check the values in a few configuration records instead of possibly thousands of node records.) Note that on systems with hyper-threading, the processor count reported by the node will be twice the actual processor count. Consider which value you want to be used for scheduling purposes.

0

Base scheduling decisions upon the actual configuration of each individual node except that the node's processor count in Slurm's configuration must match the actual hardware configuration if PreemptMode=suspend,gang or SelectType=select/cons_res are configured (both of those plugins maintain resource allocation information using bitmaps for the cores in the system and must remain static, while the node's memory and disk space can be established later).

1 (default)

Consider the configuration of each node to be that specified in the slurm.conf configuration file and any node with less than the configured resources will be set to DRAIN.

2

Consider the configuration of each node to be that specified in the slurm.conf configuration file and any node with less than the configured resources will not be set DRAIN. This option is generally only useful for testing purposes.

Used to define federation options. Multiple options may be comma separated.

fed_display

If set, then the client status commands (e.g. squeue, sinfo, sprio, etc.) will display information in a federated view by default. This option is functionally equivalent to using the --federation options on each command. Use the client's --local option to override the federated view and get a local view of the given cluster.

The job id to be used for the first submitted to Slurm without a specific requested value. Job id values generated will incremented by 1 for each subsequent job. This may be used to provide a meta-scheduler with a job id space which is disjoint from the interactive jobs. The default value is 1. Also see MaxJobId

Used for Moab scheduled jobs only. Controls how long job should wait in seconds for loading the user's environment before attempting to load it from a cache file. Applies when the srun or sbatch --get-user-env option is used. If set to 0 then always load the user's environment from the cache file. The default value is 2 seconds.

A comma delimited list of generic resources to be managed. These generic resources may have an associated plugin available to provide additional functionality. No generic resources are managed by default. Ensure this parameter is consistent across all nodes in the cluster for proper operation. The slurmctld daemon must be restarted for changes to this parameter to become effective.

If set to a non-zero value, then information about which users are members of groups allowed to use a partition will be updated periodically, even when there have been no changes to the /etc/group file. If set to zero, group member information will be updated only after the /etc/group file is updated. The default value is 1. Also see the GroupUpdateTime parameter.

Controls how frequently information about which users are members of groups allowed to use a partition will be updated, and how long user group membership lists will be cached. The time interval is given in seconds with a default value of 600 seconds. A value of zero will prevent periodic updating of group membership information. Also see the GroupUpdateForce parameter.

Identify what node states should execute the HealthCheckProgram. Multiple state values may be specified with a comma separator. The default value is ANY to execute on nodes in any state.

ALLOC

Run on nodes in the ALLOC state (all CPUs allocated).

ANY

Run on nodes in any state.

CYCLE

Rather than running the health check program on all nodes at the same time, cycle through running on all compute nodes through the course of the HealthCheckInterval. May be combined with the various node state options.

IDLE

Run on nodes in the IDLE state.

MIXED

Run on nodes in the MIXED state (some CPUs idle and other CPUs allocated).

Fully qualified pathname of a script to execute as user root periodically on all compute nodes that are not in the NOT_RESPONDING state. This program may be used to verify the node is fully operational and DRAIN the node or send email if a problem is detected. Any action to be taken must be explicitly performed by the program (e.g. execute "scontrol update NodeName=foo State=drain Reason=tmp_file_system_full" to drain a node). The execution interval is controlled using the HealthCheckInterval parameter. Note that the HealthCheckProgram will be executed at the same time on all nodes to minimize its impact upon parallel programs. This program is will be killed if it does not terminate normally within 60 seconds. This program will also be executed when the slurmd daemon is first started. By default, no program will be executed.

The interval, in seconds, after which a non-responsive job allocation command (e.g. srun or salloc) will result in the job being terminated. If the node on which the command is executed fails or the command abnormally terminates, this will terminate its job allocation. This option has no effect upon batch jobs. When setting a value, take into consideration that a debugger using srun to launch an application may leave the srun command in a stopped state for extended periods of time. This limit is ignored for jobs running in partitions with the RootOnly flag set (the scheduler running as root will be responsible for the job). The default value is unlimited (zero) and may not exceed 65533 seconds.

The job accounting mechanism type. Acceptable values at present include "jobacct_gather/linux" (for Linux systems) and is the recommended one, "jobacct_gather/cgroup" and "jobacct_gather/none" (no accounting data collected). The default value is "jobacct_gather/none". "jobacct_gather/cgroup" is a plugin for the Linux operating system that uses cgroups to collect accounting statistics. The plugin collects the following statistics: From the cgroup memory subsystem: memory.usage_in_bytes (reported as 'pages') and rss from memory.stat (reported as 'rss'). From the cgroup cpuacct subsystem: user cpu time and system cpu time. No value is provided by cgroups for virtual memory size ('vsize'). In order to use the sstat tool "jobacct_gather/linux", or "jobacct_gather/cgroup" must be configured.NOTE: Changing this configuration parameter changes the contents of the messages between Slurm daemons. Any previously running job steps are managed by a slurmstepd daemon that will persist through the lifetime of that job step and not change it's communication protocol. Only change this configuration parameter when there are no running job steps.

The job accounting and profiling sampling intervals. The supported format is follows:

JobAcctGatherFrequency=<datatype>=<interval>

where <datatype>=<interval> specifies the task sampling interval for the jobacct_gather plugin or a sampling interval for a profiling type by the acct_gather_profile plugin. Multiple, comma-separated <datatype>=<interval> intervals may be specified. Supported datatypes are as follows:

task=<interval>

where <interval> is the task sampling interval in seconds for the jobacct_gather plugins and for task profiling by the acct_gather_profile plugin.

energy=<interval>

where <interval> is the sampling interval in seconds for energy profiling using the acct_gather_energy plugin

network=<interval>

where <interval> is the sampling interval in seconds for infiniband profiling using the acct_gather_infiniband plugin.

filesystem=<interval>

where <interval> is the sampling interval in seconds for filesystem profiling using the acct_gather_filesystem plugin.

The default value for task sampling interval is 30 seconds. The default value for all other intervals is 0. An interval of 0 disables sampling of the specified type. If the task sampling interval is 0, accounting information is collected only at job termination (reducing Slurm interference with the job).

Smaller (non-zero) values have a greater impact upon job performance, but a value of 30 seconds is not likely to be noticeable for applications having less than 10,000 tasks.

Users can independently override each interval on a per job basis using the --acctg-freq option when submitting the job.

Use PSS value instead of RSS to calculate real usage of memory. The PSS value will be saved as RSS.

NoOverMemoryKill

Do not kill process that uses more then requested memory. This parameter should be used with caution as if jobs exceeds its memory allocation it may affect other processes and/or machine health. NOTE: It is recommended to limit memory by enabling task/cgroup in TaskPlugin and making use of ConstrainRAMSpace=yes cgroup.conf. If so, having JobAcctGather as an extra mechanism for memory enforcement is not recommended, so setting NoOverMemoryKill is advised.

Specifies the default directory for storing or reading job checkpoint information. The data stored here is only a few thousand bytes per job and includes information needed to resubmit the job request, not job's memory image. The directory must be readable and writable by SlurmUser, but not writable by regular users. The job memory images may be in a different location as specified by --checkpoint-dir option at job submit time or scontrol's ImageDir option.

The fully qualified file name where job completion records are written when the JobCompType is "jobcomp/filetxt" or the database where job completion records are stored when the JobCompType is a database, or an url with format http://yourelasticserver:port when JobCompType is "jobcomp/elasticsearch". NOTE: when you specify a URL for Elasticsearch, Slurm will remove any trailing slashes "/" from the configured URL and append "/slurm/jobcomp", which are the Elasticsearch index name (slurm) and mapping (jobcomp). NOTE: More information is available at the Slurm web site ( https://slurm.schedmd.com/elasticsearch.html ). Also see DefaultStorageLoc.

The job completion logging mechanism type. Acceptable values at present include "jobcomp/none", "jobcomp/elasticsearch", "jobcomp/filetxt", "jobcomp/mysql" and "jobcomp/script"". The default value is "jobcomp/none", which means that upon job completion the record of the job is purged from the system. If using the accounting infrastructure this plugin may not be of interest since the information here is redundant. The value "jobcomp/elasticsearch" indicates that a record of the job should be written to an Elasticsearch server specified by the JobCompLoc parameter. NOTE: More information is available at the Slurm web site ( https://slurm.schedmd.com/elasticsearch.html ). The value "jobcomp/filetxt" indicates that a record of the job should be written to a text file specified by the JobCompLoc parameter. The value "jobcomp/mysql" indicates that a record of the job should be written to a MySQL or MariaDB database specified by the JobCompLoc parameter. The value "jobcomp/script" indicates that a script specified by the JobCompLoc parameter is to be executed with environment variables indicating the job information.

Identifies the plugin to be used for job tracking. The slurmd daemon must be restarted for a change in JobContainerType to take effect. NOTE: The JobContainerType applies to a job allocation, while ProctrackType applies to job steps. Acceptable values at present include:

This option controls what to do if a job's output or error file exist when the job is started. If JobFileAppend is set to a value of 1, then append to the existing file. By default, any existing file is truncated.

This option controls the default ability for batch jobs to be requeued. Jobs may be requeued explicitly by a system administrator, after node failure, or upon preemption by a higher priority job. If JobRequeue is set to a value of 1, then batch job may be requeued unless explicitly disabled by the user. If JobRequeue is set to a value of 0, then batch job will not be requeued unless explicitly enabled by the user. Use the sbatch--no-requeue or --requeue option to change the default behavior for individual jobs. The default value is 1.

A comma delimited list of job submission plugins to be used. The specified plugins will be executed in the order listed. These are intended to be site-specific plugins which can be used to set default job parameters and/or logging events. Sample plugins available in the distribution include "all_partitions", "defaults", "logging", "lua", and "partition". For examples of use, see the Slurm code in "src/plugins/job_submit" and "contribs/lua/job_submit*.lua" then modify the code to satisfy your needs. Slurm can be configured to use multiple job_submit plugins if desired, however the lua plugin will only execute one lua script named "job_submit.lua" located in the default script directory (typically the subdirectory "etc" of the installation directory). No job submission plugins are used by default.

Specifies how long sockets communications used between the srun command and its slurmstepd process are kept alive after disconnect. Longer values can be used to improve reliability of communications in the event of network failures. The default value leaves the system default value. The value may not exceed 65533.

If set to 1, a step will be terminated immediately if any task is crashed or aborted, as indicated by a non-zero exit code. With the default value of 0, if one of the processes is crashed or aborted the other processes will continue to run while the crashed or aborted process waits. The user can override this configuration parameter by using srun's -K, --kill-on-bad-exit.

The interval, in seconds, given to a job's processes between the SIGTERM and SIGKILL signals upon reaching its time limit. If the job fails to terminate gracefully in the interval specified, it will be forcibly terminated. The default value is 30 seconds. The value may not exceed 65533.

Identifies the plugins to be used for support of node features which can change through time. For example, a node which might be booted with various BIOS setting. This is supported through the use of a node's active_features and available_features information. Acceptable values at present include:

node_features/knl_cray

used only for Intel Knights Landing processors (KNL) on Cray systems

node_features/knl_generic

used for Intel Knights Landing processors (KNL) on a generic Linux system

Set the cpu frequency for the batch step from given --cpu-freq, or slurm.conf CpuFreqDef, option. By default only steps started with srun will utilize the cpu freq setting options.

NOTE: If you are using srun to launch your steps inside a batch script (advised) this option will create a situation where you may have multiple agents setting the cpu_freq as the batch step usually runs on the same resources one or more steps the sruns in the script will create.

cray_net_exclusive

Allow jobs on a Cray Native cluster exclusive access to network resources. This should only be set on clusters providing exclusive access to each node to a single job at once, and not using parallel steps within the job, otherwise resources on the node can be oversubscribed.

lustre_no_flush

If set on a Cray Native cluster, then do not flush the Lustre cache on job step completion. This setting will only take effect after reconfiguring, and will only take effect for newly launched jobs.

mem_sort

Sort NUMA memory at step start. User can override this default with SLURM_MEM_BIND environment variable or --mem-bind=nosort command line option.

send_gids

Lookup and send the user_name and extended gids for a job within the slurmctld, rather than individual on each node as part of each task launch. Should avoid issues around name service scalability when launching jobs involving many nodes.

slurmstepd_memlock

Lock the slurmstepd process's current memory in RAM.

slurmstepd_memlock_all

Lock the slurmstepd process's current and future memory in RAM.

test_exec

Validate the executable command's existence prior to attempting launch on the compute nodes

Specification of licenses (or other resources available on all nodes of the cluster) which can be allocated to jobs. License names can optionally be followed by a colon and count with a default count of one. Multiple license names should be comma separated (e.g. "Licenses=foo:4,bar"). Note that Slurm prevents jobs from being scheduled if their required license specification is not available. Slurm does not prevent jobs from using licenses that are not explicitly listed in the job submission specification.

Format of the timestamp in slurmctld and slurmd log files. Accepted values are "iso8601", "iso8601_ms", "rfc5424", "rfc5424_ms", "clock", "short" and "thread_id". The values ending in "_ms" differ from the ones without in that fractional seconds with millisecond precision are printed. The default value is "iso8601_ms". The "rfc5424" formats are the same as the "iso8601" formats except that the timezone value is also shown. The "clock" format shows a timestamp in microseconds retrieved with the C standard clock() function. The "short" format is a short date and time format. The "thread_id" format shows the timestamp in the C standard ctime() function form without the year but including the microseconds, the daemon's process ID and the current thread name and ID.

The maximum job array size. The maximum job array task index value will be one less than MaxArraySize to allow for an index value of zero. Configure MaxArraySize to 0 in order to disable job array use. The value may not exceed 4000001. The value of MaxJobCount should be much larger than MaxArraySize. The default value is 1001.

The maximum number of jobs Slurm can have in its active database at one time. Set the values of MaxJobCount and MinJobAge to ensure the slurmctld daemon does not exhaust its memory or other resources. Once this limit is reached, requests to submit additional jobs will fail. The default value is 10000 jobs. NOTE: Each task of a job array counts as one job even though they will not occupy separate job records until modified or initiated. Performance can suffer with more than a few hundred thousand jobs. Setting per MaxSubmitJobs per user is generally valuable to prevent a single user from filling the system with jobs. This is accomplished using Slurm's database and configuring enforcement of resource limits. This value may not be reset via "scontrol reconfig". It only takes effect upon restart of the slurmctld daemon.

The maximum job id to be used for jobs submitted to Slurm without a specific requested value. Job ids are unsigned 32bit integers with the first 26 bits reserved for local job ids and the remaining 6 bits reserved for a cluster id to identify a federated job's origin. The maximun allowed local job id is 67,108,863 (0x3FFFFFF). The default value is 67,043,328 (0x03ff0000). MaxJobId only applies to the local job id and not the federated job id. Job id values generated will be incremented by 1 for each subsequent job. Once MaxJobId is reached, the next job will be assigned FirstJobId. Federated jobs will always have a job ID of 67,108,865 or higher. Also see FirstJobId.

Maximum real memory size available per allocated CPU in megabytes. Used to avoid over-subscribing memory and causing paging. MaxMemPerCPU would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). The default value is 0 (unlimited). Also see DefMemPerCPU and MaxMemPerNode. MaxMemPerCPU and MaxMemPerNode are mutually exclusive.

NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

NOTE: If a job specifies a memory per CPU limit that exceeds this system limit, that job's count of CPUs per task will automatically be increased. This may result in the job failing due to CPU count limits.

Maximum real memory size available per allocated node in megabytes. Used to avoid over-subscribing memory and causing paging. MaxMemPerNode would generally be used if whole nodes are allocated to jobs (SelectType=select/linear) and resources are over-subscribed (OverSubscribe=yes or OverSubscribe=force). The default value is 0 (unlimited). Also see DefMemPerNode and MaxMemPerCPU. MaxMemPerCPU and MaxMemPerNode are mutually exclusive.

NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

MCS = Multi-Category Security MCS Plugin Parameters. The supported parameters are specific to the MCSPlugin. Changes to this value take effect when the Slurm daemons are reconfigured. More information about MCS is available here <https://slurm.schedmd.com/mcs.html>.

If set to "no" then Slurm will not terminate the job or the job step if they exceeds the value requested using the --mem-per-cpu option of salloc/sbatch/srun. This is useful if jobs need to specify --mem-per-cpu for scheduling but they should not be terminate if they exceed the estimated value. The default value is 'yes', terminate the job/step if exceed the requested memory.

The minimum age of a completed job before its record is purged from Slurm's active database. Set the values of MaxJobCount and to ensure the slurmctld daemon does not exhaust its memory or other resources. The default value is 300 seconds. A value of zero prevents any job record purging. In order to eliminate some possible race conditions, the minimum non-zero value for MinJobAge recommended is 2.

Identifies the default type of MPI to be used. Srun may override this configuration parameter in any case. Currently supported versions include: openmpi, pmi2, pmix, and none (default, which works for many other versions of MPI). More information about MPI use is available here <https://slurm.schedmd.com/mpi_guide.html>.

MPI parameters. Used to identify ports used by older versions of OpenMPI and native Cray systems. The input format is "ports=12000-12999" to identify a range of communication ports to be used. NOTE: This is not needed for modern versions of OpenMPI, taking it out can cause a small boost in scheduling performance. NOTE: This is require for Cray's PMI.

Message aggregation parameters. Message aggregation is an optional feature that may improve system performance by reducing the number of separate messages passed between nodes. The feature works by routing messages through one or more message collector nodes between their source and destination nodes. At each collector node, messages with the same destination received during a defined message collection window are packaged into a single composite message. When the window expires, the composite message is sent to the next collector node on the route to its destination. The route between each source and destination node is provided by the Route plugin. When a composite message is received at its destination node, the original messages are extracted and processed as if they had been sent directly.

where <option>=<value> specify a particular control variable. Multiple, comma-separated <option>=<value> pairs may be specified. Supported options are as follows:

WindowMsgs=<number>

where <number> is the maximum number of messages in each message collection window.

WindowTime=<time>

where <time> is the maximum elapsed time in milliseconds of each message collection window.

A window expires when either WindowMsgs or WindowTime is reached. By default, message aggregation is disabled. To enable the feature, set WindowMsgs to a value greater than 1. The default value for WindowTime is 100 milliseconds.

Number of minutes by which a job can exceed its time limit before being canceled. The configured job time limit is treated as a soft limit. Adding OverTimeLimit to the soft limit provides a hard limit, at which point the job is canceled. This is particularly useful for backfill scheduling, which bases upon each job's soft time limit. The default value is zero. May not exceed exceed 65533 minutes. A value of "UNLIMITED" is also supported.

Location of the config file for Slurm stackable plugins that use the Stackable Plugin Architecture for Node job (K)control (SPANK). This provides support for a highly configurable set of plugins to be called before and/or after execution of each task spawned as part of a user's job step. Default location is "plugstack.conf" in the same directory as the system slurm.conf. For more information on SPANK plugins, see the spank(8) manual.

System power management parameters. The supported parameters are specific to the PowerPlugin. Changes to this value take effect when the Slurm daemons are reconfigured. More information about system power management is available here <https://slurm.schedmd.com/power_mgmt.html>. Options current supported by any plugins are listed below.

balance_interval=#

Specifies the time interval, in seconds, between attempts to rebalance power caps across the nodes. This also controls the frequency at which Slurm attempts to collect current power consumption data (old data may be used until new data is available from the underlying infrastructure and values below 10 seconds are not recommended for Cray systems). The default value is 30 seconds. Supported by the power/cray plugin.

capmc_path=

Specifies the absolute path of the capmc command. The default value is "/opt/cray/capmc/default/bin/capmc". Supported by the power/cray plugin.

cap_watts=#

Specifies the total power limit to be established across all compute nodes managed by Slurm. A value of 0 sets every compute node to have an unlimited cap. The default value is 0. Supported by the power/cray plugin.

decrease_rate=#

Specifies the maximum rate of change in the power cap for a node where the actual power usage is below the power cap by an amount greater than lower_threshold (see below). Value represents a percentage of the difference between a node's minimum and maximum power consumption. The default value is 50 percent. Supported by the power/cray plugin.

get_timeout=#

Amount of time allowed to get power state information in milliseconds. The default value is 5,000 milliseconds or 5 seconds. Supported by the power/cray plugin and represents the time allowed for the capmc command to respond to various "get" options.

increase_rate=#

Specifies the maximum rate of change in the power cap for a node where the actual power usage is within upper_threshold (see below) of the power cap. Value represents a percentage of the difference between a node's minimum and maximum power consumption. The default value is 20 percent. Supported by the power/cray plugin.

job_level

All nodes associated with every job will have the same power cap, to the extent possible. Also see the --power=level option on the job submission commands.

job_no_level

Disable the user's ability to set every node associated with a job to the same power cap. Each node will have it's power cap set independently. This disables the --power=level option on the job submission commands.

lower_threshold=#

Specify a lower power consumption threshold. If a node's current power consumption is below this percentage of its current cap, then its power cap will be reduced. The default value is 90 percent. Supported by the power/cray plugin.

recent_job=#

If a job has started or resumed execution (from suspend) on a compute node within this number of seconds from the current time, the node's power cap will be increased to the maximum. The default value is 300 seconds. Supported by the power/cray plugin.

set_timeout=#

Amount of time allowed to set power state information in milliseconds. The default value is 30,000 milliseconds or 30 seconds. Supported by the power/cray plugin and represents the time allowed for the capmc command to respond to various "set" options.

set_watts=#

Specifies the power limit to be set on every compute nodes managed by Slurm. Every node gets this same power cap and there is no variation through time based upon actual power usage on the node. Supported by the power/cray plugin.

upper_threshold=#

Specify an upper power consumption threshold. If a node's current power consumption is above this percentage of its current cap, then its power cap will be increased to the extent possible. The default value is 95 percent. Supported by the power/cray plugin.

Identifies the plugin used for system power management. Currently supported plugins include: cray and none. Changes to this value require restarting Slurm daemons to take effect. More information about system power management is available here <https://slurm.schedmd.com/power_mgmt.html>. By default, no power plugin is loaded.

Enables gang scheduling and/or controls the mechanism used to preempt jobs. When the PreemptType parameter is set to enable preemption, the PreemptMode selects the default mechanism used to preempt the lower priority jobs for the cluster. PreemptMode may be specified on a per partition basis to override this default value if PreemptType=preempt/partition_prio, but a valid default PreemptMode value must be specified for the cluster as a whole when preemption is enabled. The GANG option is used to enable gang scheduling independent of whether preemption is enabled (the PreemptType setting). The GANG option can be specified in addition to a PreemptMode setting with the two options comma separated. The SUSPEND option requires that gang scheduling be enabled (i.e, "PreemptMode=SUSPEND,GANG").

OFF

is the default value and disables job preemption and gang scheduling.

CANCEL

always cancel the job.

CHECKPOINT

preempts jobs by checkpointing them (if possible) or canceling them.

GANG

enables gang scheduling (time slicing) of jobs in the same partition. NOTE: Gang scheduling is performed independently for each partition, so configuring partitions with overlapping nodes and gang scheduling is generally not recommended.

REQUEUE

preempts jobs by requeuing them (if possible) or canceling them. For jobs to be requeued they must have the --requeue sbatch option set or the cluster wide JobRequeue parameter in slurm.conf must be set to one.

SUSPEND

If PreemptType=preempt/partition_prio is configured then suspend and automatically resume the low priority jobs. If PreemptType=preempt/qos is configured, then the jobs sharing resources will always time slice rather than one job remaining suspended. The SUSPEND may only be used with the GANG option (the gang scheduler module performs the job resume operation).

This specifies the plugin used to identify which jobs can be preempted in order to start a pending job.

preempt/none

Job preemption is disabled. This is the default.

preempt/partition_prio

Job preemption is based upon partition priority tier. Jobs in higher priority partitions (queues) may preempt jobs from lower priority partitions. This is not compatible with PreemptMode=OFF.

preempt/qos

Job preemption rules are specified by Quality Of Service (QOS) specifications in the Slurm database. This option is not compatible with PreemptMode=OFF. A configuration of PreemptMode=SUSPEND is only supported by the select/cons_res plugin.

This controls how long prior resource use is considered in determining how over- or under-serviced an association is (user, bank account and cluster) in determining job priority. The record of usage will be decayed over time, with half of the original value cleared at age PriorityDecayHalfLife. If set to 0 no decay will be applied. This is helpful if you want to enforce hard time limits per association. If set to 0 PriorityUsageResetPeriod must be set to some interval. Applicable only if PriorityType=priority/multifactor. The unit is a time string (i.e. min, hr:min:00, days-hr:min:00, or days-hr). The default value is 7-0 (7 days).

Flags to modify priority behavior Applicable only if PriorityType=priority/multifactor. The keywords below have no associated value (e.g. "PriorityFlags=ACCRUE_ALWAYS,SMALL_RELATIVE_TO_TIME").

ACCRUE_ALWAYS

If set, priority age factor will be increased despite job dependencies or holds.

CALCULATE_RUNNING

If set, priorities will be recalculated not only for pending jobs, but also running and suspended jobs.

DEPTH_OBLIVIOUS

If set, priority will be calculated based similar to the normal multifactor calculation, but depth of the associations in the tree do not adversely effect their priority. This option precludes the use of FAIR_TREE.

FAIR_TREE

If set, priority will be calculated in such a way that if accounts A and B are siblings and A has a higher fairshare factor than B, all children of A will have higher fairshare factors than all children of B.

INCR_ONLY

If set, priority values will only increase in value. Job priority will never decrease in value.

MAX_TRES

If set, the weighted TRES value (e.g. TRESBillingWeights) is calculated as the MAX of individual TRES' on a node (e.g. cpus, mem, gres) plus the sum of all global TRES' (e.g. licenses).

SMALL_RELATIVE_TO_TIME

If set, the job's size component will be based upon not the job size alone, but the job's size divided by it's time limit.

Specifies the job age which will be given the maximum age factor in computing priority. For example, a value of 30 minutes would result in all jobs over 30 minutes old would get the same age-based priority. Applicable only if PriorityType=priority/multifactor. The unit is a time string (i.e. min, hr:min:00, days-hr:min:00, or days-hr). The default value is 7-0 (7 days).

At this interval the usage of associations will be reset to 0. This is used if you want to enforce hard limits of time usage per association. If PriorityDecayHalfLife is set to be 0 no decay will happen and this is the only way to reset the usage accumulated by running jobs. By default this is turned off and it is advised to use the PriorityDecayHalfLife option to avoid not having anything running on your cluster, but if your schema is set up to only allow certain amounts of time on your system this is the way to do it. Applicable only if PriorityType=priority/multifactor.

This specifies the plugin to be used in establishing a job's scheduling priority. Supported values are "priority/basic" (jobs are prioritized by order of arrival), "priority/multifactor" (jobs are prioritized based upon size, age, fair-share of allocation, etc). Also see PriorityFlags for configuration options. The default value is "priority/basic".

When not FIFO scheduling, jobs are prioritized in the following order:

This controls what type of information is hidden from regular users. By default, all information is visible to all users. User SlurmUser and root can always view all information. Multiple values may be specified with a comma separator. Acceptable values include:

accounts

(NON-SlurmDBD ACCOUNTING ONLY) Prevents users from viewing any account definitions unless they are coordinators of them.

cloud

Powered down nodes in the cloud are visible.

events

prevents users from viewing event information unless they have operator status or above.

jobs

Prevents users from viewing jobs or job steps belonging to other users. (NON-SlurmDBD ACCOUNTING ONLY) Prevents users from viewing job records belonging to other users unless they are coordinators of the association running the job when using sacct.

nodes

Prevents users from viewing node state information.

partitions

Prevents users from viewing partition state information.

reservations

Prevents regular users from viewing reservations which they can not use.

usage

Prevents users from viewing usage of any other user, this applies to sshare. (NON-SlurmDBD ACCOUNTING ONLY) Prevents users from viewing usage of any other user, this applies to sreport.

users

(NON-SlurmDBD ACCOUNTING ONLY) Prevents users from viewing information of any user other than themselves, this also makes it so users can only see associations they deal with. Coordinators can see associations of all users they are coordinator of, but can only see themselves when listing users.

Identifies the plugin to be used for process tracking on a job step basis. The slurmd daemon uses this mechanism to identify all processes which are children of processes it spawns for a user job step. The slurmd daemon must be restarted for a change in ProctrackType to take effect. NOTE: "proctrack/linuxproc" and "proctrack/pgid" can fail to identify all processes associated with a job since processes can become a child of the init process (when the parent process terminates) or change their process group. To reliably track all processes, "proctrack/cgroup" is highly recommended. NOTE: The JobContainerType applies to a job allocation, while ProctrackType applies to job steps. Acceptable values at present include:

proctrack/cgroup

which uses linux cgroups to constrain and track processes, and is the default. NOTE: see "man cgroup.conf" for configuration details

Fully qualified pathname of a program for the slurmd to execute whenever it is asked to run a job step from a new job allocation (e.g. "/usr/local/slurm/prolog"). A glob pattern (See glob (7)) may also be used to specify more than one program to run (e.g. "/etc/slurm/prolog.d/*"). The slurmd executes the prolog before starting the first job step. The prolog script or scripts may be used to purge files, enable user login, etc. By default there is no prolog. Any configured script is expected to complete execution quickly (in less time than MessageTimeout). If the prolog fails (returns a non-zero exit code), this will result in the node being set to a DRAIN state and the job being requeued in a held state, unless nohold_on_prolog_fail is configured in SchedulerParameters. See Prolog and Epilog Scripts for more information.

The interval in seconds Slurms waits for Prolog and Epilog before terminating them. The default behavior is to wait indefinitely. This interval applies to the Prolog and Epilog run by slurmd daemon before and after the job, the PrologSlurmctld and EpilogSlurmctld run by slurmctld daemon, and the SPANK plugins run by the slurmstepd daemon.

Flags to control the Prolog behavior. By default no flags are set. Multiple flags may be specified in a comma-separated list. Currently supported options are:

Alloc

If set, the Prolog script will be executed at job allocation. By default, Prolog is executed just before the task is launched. Therefore, when salloc is started, no Prolog is executed. Alloc is useful for preparing things before a user starts to use any allocated resources. In particular, this flag is needed on a Cray system when cluster compatibility mode is enabled.

NOTE: Use of the Alloc flag will increase the time required to start jobs.

Contain

At job allocation time, use the ProcTrack plugin to create a job container on all allocated compute nodes. This container may be used for user processes not launched under Slurm control, for example the PAM module may place processes launch through a direct user login into this container. Setting the Contain implicitly sets the Alloc flag.

NoHold

If set, the Alloc flag should also be set. This will allow for salloc to not block until the prolog is finished on each node. The blocking will happen when steps reach the slurmd and before any execution has happened in the step. This is a much faster way to work and if using srun to launch your tasks you should use this flag.

Serial

By default, the Prolog and Epilog scripts run concurrently on each node. This flag forces those scripts to run serially within each node, but with a significant penalty to job throughput on each node.

X11

Enable Slurm's built-in X11 forwarding capabilities. Slurm must have been compiled with libssh2 support enabled, and either SSH hostkey authentication or per-users SSH key authentication must be enabled within the cluster. Only RSA keys are supported at this time. Setting the X11 flag implicitly enables both Contain and Alloc flags as well.

Fully qualified pathname of a program for the slurmctld daemon to execute before granting a new job allocation (e.g. "/usr/local/slurm/prolog_controller"). The program executes as SlurmUser on the same node where the slurmctld daemon executes, giving it permission to drain nodes and requeue the job if a failure occurs or cancel the job if appropriate. The program can be used to reboot nodes or perform other work to prepare resources for use. Exactly what the program does and how it accomplishes this is completely at the discretion of the system administrator. Information about the job being initiated, it's allocated nodes, etc. are passed to the program using environment variables. While this program is running, the nodes associated with the job will be have a POWER_UP/CONFIGURING flag set in their state, which can be readily viewed. The slurmctld daemon will wait indefinitely for this program to complete. Once the program completes with an exit code of zero, the nodes will be considered ready for use and the program will be started. If some node can not be made available for use, the program should drain the node (typically using the scontrol command) and terminate with a non-zero exit code. A non-zero exit code will result in the job being requeued (where possible) or killed. Note that only batch jobs can be requeued. See Prolog and Epilog Scripts for more information.

The tasks will inherit the scheduling priority from the slurm daemon. This is the default value.

1

The tasks will inherit the scheduling priority of the command used to submit them (e.g. srun or sbatch). Unless the job is submitted by user root, the tasks will have a scheduling priority no higher than the slurm daemon spawning them.

2

The tasks will inherit the scheduling priority of the command used to submit them (e.g. srun or sbatch) with the restriction that their nice value will always be one higher than the slurm daemon (i.e. the tasks scheduling priority will be lower than the slurm daemon).

A list of comma separated resource limit names. The slurmd daemon uses these names to obtain the associated (soft) limit values from the user's process environment on the submit node. These limits are then propagated and applied to the jobs that will run on the compute nodes. This parameter can be useful when system limits vary among nodes. Any resource limits that do not appear in the list are not propagated. However, the user can override this by specifying which resource limits to propagate with the sbatch or srun "--propagate" option. If neither PropagateResourceLimits or PropagateResourceLimitsExcept are configured and the "--propagate" option is not specified, then the default action is to propagate all limits. Only one of the parameters, either PropagateResourceLimits or PropagateResourceLimitsExcept, may be specified. The user limits can not exceed hard limits under which the slurmd daemon operates. If the user limits are not propagated, the limits from the slurmd daemon will be propagated to the user's job. The limits used for the Slurm daemons can be set in the /etc/sysconf/slurm file. For more information, see: https://slurm.schedmd.com/faq.html#memlock The following limit names are supported by Slurm (although some options may not be supported on some systems):

ALL

All limits listed below (default)

NONE

No limits listed below

AS

The maximum address space for a process

CORE

The maximum size of core file

CPU

The maximum amount of CPU time

DATA

The maximum size of a process's data segment

FSIZE

The maximum size of files created. Note that if the user sets FSIZE to less than the current size of the slurmd.log, job launches will fail with a 'File size limit exceeded' error.

A list of comma separated resource limit names. By default, all resource limits will be propagated, (as described by the PropagateResourceLimits parameter), except for the limits appearing in this list. The user can override this by specifying which resource limits to propagate with the sbatch or srun "--propagate" option. See PropagateResourceLimits above for a list of valid limit names.

Program to be executed on each compute node to reboot it. Invoked on each node once it becomes idle after the command "scontrol reboot_nodes" is executed by an authorized user or a job is submitted with the "--reboot" option. After rebooting, the node is returned to normal use. See ResumeTimeout to configure the time you expect a reboot to finish in. NOTE: This configuration option does not apply to IBM BlueGene systems.

Flags to control various actions that may be taken when an "scontrol reconfig" command is issued. Currently the options are:

KeepPartInfo

If set, an "scontrol reconfig" command will maintain the in-memory value of partition "state" and other parameters that may have been dynamically updated by "scontrol update". Partition information in the slurm.conf file will be merged with in-memory data. This flag supersedes the KeepPartState flag.

KeepPartState

If set, an "scontrol reconfig" command will preserve only the current "state" value of in-memory partitions and will reset all other parameters of the partitions that may have been dynamically updated by "scontrol update" to the values from the slurm.conf file. Partition information in the slurm.conf file will be merged with in-memory data.

The default for the above flags is not set, and the "scontrol reconfig" will rebuild the partition information using only the definitions in the slurm.conf file.

Enables automatic requeue for batch jobs which exit with the specified values. Separate multiple exit code by a comma and/or specify numeric ranges using a "-" separator (e.g. "RequeueExit=1-9,18") Jobs will be put back in to pending state and later scheduled again. Restarted jobs will have the environment variable SLURM_RESTART_COUNT set to the number of times the job has been restarted.

Enables automatic requeue for batch jobs which exit with the specified values, with these jobs being held until released manually by the user. Separate multiple exit code by a comma and/or specify numeric ranges using a "-" separator (e.g. "RequeueExitHold=10-12,16") These jobs are put in the JOB_SPECIAL_EXIT exit state. Restarted jobs will have the environment variable SLURM_RESTART_COUNT set to the number of times the job has been restarted.

Slurm supports a mechanism to reduce power consumption on nodes that remain idle for an extended period of time. This is typically accomplished by reducing voltage and frequency or powering the node down. ResumeProgram is the program that will be executed when a node in power save mode is assigned work to perform. For reasons of reliability, ResumeProgram may execute more than once for a node when the slurmctld daemon crashes and is restarted. If ResumeProgram is unable to restore a node to service with a responding slurmd and an updated BootTime, it should requeue any job associated with the node and set the node state to DOWN. If the node isn't actually rebooted (i.e. when multiple-slurmd is configured) starting slurmd with "-b" option might be useful. The program executes as SlurmUser. The argument to the program will be the names of nodes to be removed from power savings mode (using Slurm's hostlist expression format). By default no program is run. Related configuration options include ResumeTimeout, ResumeRate, SuspendRate, SuspendTime, SuspendTimeout, SuspendProgram, SuspendExcNodes, and SuspendExcParts. More information is available at the Slurm web site ( https://slurm.schedmd.com/power_save.html ).

The rate at which nodes in power save mode are returned to normal operation by ResumeProgram. The value is number of nodes per minute and it can be used to prevent power surges if a large number of nodes in power save mode are assigned work at the same time (e.g. a large job starts). A value of zero results in no limits being imposed. The default value is 300 nodes per minute. Related configuration options include ResumeTimeout, ResumeProgram, SuspendRate, SuspendTime, SuspendTimeout, SuspendProgram, SuspendExcNodes, and SuspendExcParts.

Maximum time permitted (in second) between when a node resume request is issued and when the node is actually available for use. Nodes which fail to respond in this time frame will be marked DOWN and the jobs scheduled on the node requeued. Nodes which reboot after this time frame will be marked DOWN with a reason of "unexpected reboot." The default value is 60 seconds. Related configuration options include ResumeProgram, ResumeRate, SuspendRate, SuspendTime, SuspendTimeout, SuspendProgram, SuspendExcNodes and SuspendExcParts. More information is available at the Slurm web site ( https://slurm.schedmd.com/power_save.html ).

Fully qualified pathname of a program for the slurmctld to execute when a reservation ends. The program can be used to cancel jobs, modify partition configuration, etc. The reservation named will be passed as an argument to the program. By default there is no epilog.

Describes how long a job already running in a reservation should be permitted to execute after the end time of the reservation has been reached. The time period is specified in minutes and the default value is 0 (kill the job immediately). The value may not exceed 65533 minutes, although a value of "UNLIMITED" is supported to permit a job to run indefinitely after its reservation is terminated.

Fully qualified pathname of a program for the slurmctld to execute when a reservation begins. The program can be used to cancel jobs, modify partition configuration, etc. The reservation named will be passed as an argument to the program. By default there is no prolog.

Controls when a DOWN node will be returned to service. The default value is 0. Supported values include

0

A node will remain in the DOWN state until a system administrator explicitly changes its state (even if the slurmd daemon registers and resumes communications).

1

A DOWN node will become available for use upon registration with a valid configuration only if it was set DOWN due to being non-responsive. If the node was set DOWN for any other reason (low memory, unexpected reboot, etc.), its state will not automatically be changed. A node registers with a valid configuration if its memory, GRES, CPU count, etc. are equal to or greater than the values configured in slurm.conf.

2

A DOWN node will become available for use upon registration with a valid configuration. The node could have been set DOWN for any reason. A node registers with a valid configuration if its memory, GRES, CPU count, etc. are equal to or greater than the values configured in slurm.conf. (Disabled on Cray ALPS systems.)

Normally, salloc(1) will run the user's default shell when a command to execute is not specified on the salloc command line. If SallocDefaultCommand is specified, salloc will instead run the configured command. The command is passed to '/bin/sh -c', so shell metacharacters are allowed, and commands with multiple arguments should be quoted. For instance:

would run spawn the user's default shell on the allocated resources, but not consume any of the CPU or memory resources, configure it as a pseudo-terminal, and preserve all of the job's environment variables (i.e. and not over-write them with the job step's allocation information).

For systems with generic resources (GRES) defined, the SallocDefaultCommand value should explicitly specify a zero count for the configured GRES. Failure to do so will result in the launched shell consuming those GRES and preventing subsequent srun commands from using them. For example, on Cray systems add "--gres=craynetwork:0" as shown below:

For systems with TaskPlugin set, adding an option of "--cpu-bind=no" is recommended if the default shell should have access to all of the CPUs allocated to the job on that node, otherwise the shell may be limited to a single cpu or core.

Destination directory for file being broadcast to allocated compute nodes. Default value is current working directory.

Compression=

Specify default file compression library to be used. Supported values are "lz4", "none" and "zlib". The default value with the sbcast --compress option is "lz4" and "none" otherwise. Some compression libraries may be unavailable on some systems.

The interpretation of this parameter varies by SchedulerType. Multiple options may be comma separated.

assoc_limit_stop

If set and a job cannot start due to association limits, then do not attempt to initiate any lower priority jobs in that partition. Setting this can decrease system throughput and utilization, but avoid potentially starving larger jobs by preventing them from launching indefinitely.

batch_sched_delay=#

How long, in seconds, the scheduling of batch jobs can be delayed. This can be useful in a high-throughput environment in which batch jobs are submitted at a very high rate (i.e. using the sbatch command) and one wishes to reduce the overhead of attempting to schedule each job at submit time. The default value is 3 seconds.

bb_array_stage_cnt=#

Number of tasks from a job array that should be available for burst buffer resource allocation. Higher values will increase the system overhead as each task from the job array will be moved to it's own job record in memory, so relatively small values are generally recommended. The default value is 10.

bf_busy_nodes

When selecting resources for pending jobs to reserve for future execution (i.e. the job can not be started immediately), then preferentially select nodes that are in use. This will tend to leave currently idle resources available for backfilling longer running jobs, but may result in allocations having less than optimal network topology. This option is currently only supported by the select/cons_res plugin (or select/cray with SelectTypeParameters set to "OTHER_CONS_RES", which layers the select/cray plugin over the select/cons_res plugin).

bf_continue

The backfill scheduler periodically releases locks in order to permit other operations to proceed rather than blocking all activity for what could be an extended period of time. Setting this option will cause the backfill scheduler to continue processing pending jobs from its original job list after releasing locks even if job or node state changes. This can result in lower priority jobs being backfill scheduled instead of newly arrived higher priority jobs, but will permit more queued jobs to be considered for backfill scheduling.

bf_interval=#

The number of seconds between backfill iterations. Higher values result in less overhead and better responsiveness. This option applies only to SchedulerType=sched/backfill. The default value is 30 seconds.

bf_job_part_count_reserve=#

The backfill scheduling logic will reserve resources for the specified count of highest priority jobs in each partition. For example, bf_job_part_count_reserve=10 will cause the backfill scheduler to reserve resources for the ten highest priority jobs in each partition. Any lower priority job that can be started using currently available resources and not adversely impact the expected start time of these higher priority jobs will be started by the backfill scheduler The default value is zero, which will reserve resources for any pending job and delay initiation of lower priority jobs. Also see bf_min_age_reserve and bf_min_prio_reserve.

bf_max_job_array_resv=#

The maximum number of tasks from a job array for which the backfill scheduler will reserve resources in the future. Since job arrays can potentially have millions of tasks, the overhead in reserving resources for all tasks can be prohibitive. In addition various limits may prevent all the jobs from starting at the expected times. This has no impact upon the number of tasks from a job array that can be started immediately, only those tasks expected to start at some future time. The default value is 20 tasks.

bf_max_job_assoc=#

The maximum number of jobs per user association to attempt starting with the backfill scheduler. This setting is similar to to bf_max_job_user but is handy if a user has multiple assocations equating to basically different users. One can set this limit to prevent users from flooding the backfill queue with jobs that cannot start and that prevent jobs from other users to start. The default value is 0, which means no limit. This option applies only to SchedulerType=sched/backfill. Also see the bf_max_job_user bf_max_job_part, bf_max_job_test and bf_max_job_user_part=# options. Set bf_max_job_test to a value much higher than bf_max_job_assoc.

bf_max_job_part=#

The maximum number of jobs per partition to attempt starting with the backfill scheduler. This can be especially helpful for systems with large numbers of partitions and jobs. The default value is 0, which means no limit. This option applies only to SchedulerType=sched/backfill. Also see the partition_job_depth and bf_max_job_test options. Set bf_max_job_test to a value much higher than bf_max_job_part.

bf_max_job_start=#

The maximum number of jobs which can be initiated in a single iteration of the backfill scheduler. The default value is 0, which means no limit. This option applies only to SchedulerType=sched/backfill.

bf_max_job_test=#

The maximum number of jobs to attempt backfill scheduling for (i.e. the queue depth). Higher values result in more overhead and less responsiveness. Until an attempt is made to backfill schedule a job, its expected initiation time value will not be set. The default value is 100. In the case of large clusters, configuring a relatively small value may be desirable. This option applies only to SchedulerType=sched/backfill.

bf_max_job_user=#

The maximum number of jobs per user to attempt starting with the backfill scheduler for ALL partitions. One can set this limit to prevent users from flooding the backfill queue with jobs that cannot start and that prevent jobs from other users to start. This is similar to the MAXIJOB limit in Maui. The default value is 0, which means no limit. This option applies only to SchedulerType=sched/backfill. Also see the bf_max_job_part, bf_max_job_test and bf_max_job_user_part=# options. Set bf_max_job_test to a value much higher than bf_max_job_user.

bf_max_job_user_part=#

The maximum number of jobs per user per partition to attempt starting with the backfill scheduler for any single partition. The default value is 0, which means no limit. This option applies only to SchedulerType=sched/backfill. Also see the bf_max_job_part, bf_max_job_test and bf_max_job_user=# options.

bf_max_time=#

The maximum time the backfill scheduler can spend (including time spent sleeping when locks are released) before discontinuing, even if maximum job counts have not been reached. This option applies only to SchedulerType=sched/backfill. The default value is the value of bf_interval (which defaults to 30 seconds). NOTE: This needs to be high enough that scheduling isn't always disabled, and low enough that our interactive workload can get through in a reasonable period of time. Certainly needs to be below 256 (the default RPC thread limit). Running around the middle (150) may give you good results.

bf_min_age_reserve=#

The backfill and main scheduling logic will not reserve resources for pending jobs until they have been pending and runnable for at least the specified number of seconds. In addition, jobs waiting for less than the specified number of seconds will not prevent a newly submitted job from starting immediately, even if the newly submitted job has a lower priority. This can be valuable if jobs lack time limits or all time limits have the same value. The default value is zero, which will reserve resources for any pending job and delay initiation of lower priority jobs. Also see bf_job_part_count_reserve and bf_min_prio_reserve.

bf_min_prio_reserve=#

The backfill and main scheduling logic will not reserve resources for pending jobs unless they have a priority equal to or higher than the specified value. In addition, jobs with a lower priority will not prevent a newly submitted job from starting immediately, even if the newly submitted job has a lower priority. This can be valuable if one wished to maximum system utilization without regard for job priority below a certain threshold. The default value is zero, which will reserve resources for any pending job and delay initiation of lower priority jobs. Also see bf_job_part_count_reserve and bf_min_age_reserve.

bf_resolution=#

The number of seconds in the resolution of data maintained about when jobs begin and end. Higher values result in less overhead and better responsiveness. The default value is 60 seconds. This option applies only to SchedulerType=sched/backfill.

bf_window=#

The number of minutes into the future to look when considering jobs to schedule. Higher values result in more overhead and less responsiveness. The default value is 1440 minutes (one day). A value at least as long as the highest allowed time limit is generally advisable to prevent job starvation. In order to limit the amount of data managed by the backfill scheduler, if the value of bf_window is increased, then it is generally advisable to also increase bf_resolution. This option applies only to SchedulerType=sched/backfill.

bf_window_linear=#

For performance reasons, the backfill scheduler will decrease precision in calculation of job expected termination times. By default, the precision starts at 30 seconds and that time interval doubles with each evaluation of currently executing jobs when trying to determine when a pending job can start. This algorithm can support an environment with many thousands of running jobs, but can result in the expected start time of pending jobs being gradually being deferred due to lack of precision. A value for bf_window_linear will cause the time interval to be increased by a constant amount on each iteration. The value is specified in units of seconds. For example, a value of 60 will cause the backfill scheduler on the first iteration to identify the job ending soonest and determine if the pending job can be started after that job plus all other jobs expected to end within 30 seconds (default initial value) of the first job. On the next iteration, the pending job will be evaluated for starting after the next job expected to end plus all jobs ending within 90 seconds of that time (30 second default, plus the 60 second option value). The third iteration will have a 150 second window and the fourth 210 seconds. Without this option, the time windows will double on each iteration and thus be 30, 60, 120, 240 seconds, etc. The use of bf_window_linear is not recommended with more than a few hundred simultaneously executing jobs.

bf_yield_interval=#

The backfill scheduler will periodically relinquish locks in order for other pending operations to take place. This specifies the times when the locks are relinquish in microseconds. The default value is 2,000,000 microseconds (2 seconds). Smaller values may be helpful for high throughput computing when used in conjunction with the bf_continue option. Also see the bf_yield_sleep option.

bf_yield_sleep=#

The backfill scheduler will periodically relinquish locks in order for other pending operations to take place. This specifies the length of time for which the locks are relinquish in microseconds. The default value is 500,000 microseconds (0.5 seconds). Also see the bf_yield_interval option.

build_queue_timeout=#

Defines the maximum time that can be devoted to building a queue of jobs to be tested for scheduling. If the system has a huge number of jobs with dependencies, just building the job queue can take so much time as to adversely impact overall system performance and this parameter can be adjusted as needed. The default value is 2,000,000 microseconds (2 seconds).

default_queue_depth=#

The default number of jobs to attempt scheduling (i.e. the queue depth) when a running job completes or other routine actions occur, however the frequency with which the scheduler is run may be limited by using the defer or sched_min_interval parameters described below. The full queue will be tested on a less frequent basis as defined by the sched_interval option described below. The default value is 100. See the partition_job_depth option to limit depth by partition.

defer

Setting this option will avoid attempting to schedule each job individually at job submit time, but defer it until a later time when scheduling multiple jobs simultaneously may be possible. This option may improve system responsiveness when large numbers of jobs (many hundreds) are submitted at the same time, but it will delay the initiation time of individual jobs. Also see default_queue_depth above.

delay_boot=#

Do not reboot nodes in order to satisfied this job's feature specification if the job has been eligible to run for less than this time period. If the job has waited for less than the specified period, it will use only nodes which already have the specified features. The argument is in units of minutes. Individual jobs may override this default value with the --delay-boot option.

default_gbytes

The default units in job submission memory and temporary disk size specification will be gigabytes rather than megabytes. Users can override the default by using a suffix of "M" for megabytes.

disable_hetero_steps

Disable job steps that span heterogeneous job allocations, even with the mpi/none plugin.

enable_hetero_steps

Enable job steps that span heterogeneous job allocations.

enable_user_top

Enable use of the "scontrol top" command by non-privileged users.

Ignore_NUMA

Some processors (e.g. AMD Opteron 6000 series) contain multiple NUMA nodes per socket. This is a configuration which does not map into the hardware entities that Slurm optimizes resource allocation for (PU/thread, core, socket, baseboard, node and network switch). In order to optimize resource allocations on such hardware, Slurm will consider each NUMA node within the socket as a separate socket by default. Use the Ignore_NUMA option to report the correct socket count, but not optimize resource allocations on the NUMA nodes.

inventory_interval=#

On a Cray system using Slurm on top of ALPS this limits the number of times a Basil Inventory call is made. Normally this call happens every scheduling consideration to attempt to close a node state change window with respects to what ALPS has. This call is rather slow, so making it less frequently improves performance dramatically, but in the situation where a node changes state the window is as large as this setting. In an HTC environment this setting is a must and we advise around 10 seconds.

kill_invalid_depend

If a job has an invalid dependency and it can never run terminate it and set its state to be JOB_CANCELLED. By default the job stays pending with reason DependencyNeverSatisfied.

max_array_tasks

Specify the maximum number of tasks that be included in a job array. The default limit is MaxArraySize, but this option can be used to set a lower limit. For example, max_array_tasks=1000 and MaxArraySize=100001 would permit a maximum task ID of 100000, but limit the number of tasks in any single job array to 1000.

max_depend_depth=#

Maximum number of jobs to test for a circular job dependency. Stop testing after this number of job dependencies have been tested. The default value is 10 jobs.

max_rpc_cnt=#

If the number of active threads in the slurmctld daemon is equal to or larger than this value, defer scheduling of jobs. This can improve Slurm's ability to process requests at a cost of initiating new jobs less frequently. The default value is zero, which disables this option. If a value is set, then a value of 10 or higher is recommended.

max_sched_time=#

How long, in seconds, that the main scheduling loop will execute for before exiting. If a value is configured, be aware that all other Slurm operations will be deferred during this time period. Make certain the value is lower than MessageTimeout. If a value is not explicitly configured, the default value is half of MessageTimeout with a minimum default value of 1 second and a maximum default value of 2 seconds. For example if MessageTimeout=10, the time limit will be 2 seconds (i.e. MIN(10/2, 2) = 2).

max_script_size=#

Specify the maximum size of a batch script, in bytes. The default value is 4 megabytes. Larger values may adversely impact system performance.

max_switch_wait=#

Maximum number of seconds that a job can delay execution waiting for the specified desired switch count. The default value is 300 seconds.

no_backup_scheduling

If used, the backup controller will not schedule jobs when it takes over. The backup controller will allow jobs to be submitted, modified and cancelled but won't schedule new jobs. This is useful in Cray environments when the backup controller resides on an external Cray node. A restart is required to alter this option. This is explicitly set on a Cray/ALPS system.

no_env_cache

If used, any job started on node that fails to load the env from a node will fail instead of using the cached env. This will also implicitly imply the requeue_setup_env_fail option as well.

pack_serial_at_end

If used with the select/cons_res plugin then put serial jobs at the end of the available nodes rather than using a best fit algorithm. This may reduce resource fragmentation for some workloads.

partition_job_depth=#

The default number of jobs to attempt scheduling (i.e. the queue depth) from each partition/queue in Slurm's main scheduling logic. The functionality is similar to that provided by the bf_max_job_part option for the backfill scheduling logic. The default value is 0 (no limit). Job's excluded from attempted scheduling based upon partition will not be counted against the default_queue_depth limit. Also see the bf_max_job_part option.

preempt_reorder_count=#

Specify how many attempts should be made in reording preemptable jobs to minimize the count of jobs preempted. The default value is 1. High values may adversely impact performance. The logic to support this option is only available in the select/cons_res plugin.

preempt_strict_order

If set, then execute extra logic in an attempt to preempt only the lowest priority jobs. It may be desirable to set this configuration parameter when there are multiple priorities of preemptable jobs. The logic to support this option is only available in the select/cons_res plugin.

preempt_youngest_first

If set, then the preemption sorting algorithm will be changed to sort by the job start times to favor preempting younger jobs over older. (Requires preempt/partition_prio or preempt/qos plugins.)

nohold_on_prolog_fail

By default if the Prolog exits with a non-zero value the job is requeued in held state. By specifying this parameter the job will be requeued but not held so that the scheduler can dispatch it to another host.

reduce_completing_frag

This option is used to control how scheduling of resources is performed when jobs are in completing state, which influences potential fragmentation. If the option is not set then no jobs will be started in any partition when any job is in completing state. If the option is set then no jobs will be started in any individual partition that has a job in completing state. In addition, no jobs will be started in any partition with nodes that overlap with any nodes in the partition of the completing job. This option is to be used in conjunction with CompleteWait. NOTE: CompleteWait must be set for this to work.

requeue_setup_env_fail

By default if a job environment setup fails the job keeps running with a limited environment. By specifying this parameter the job will be requeued in held state and the execution node drained.

salloc_wait_nodes

If defined, the salloc command will wait until all allocated nodes are ready for use (i.e. booted) before the command returns. By default, salloc will return as soon as the resource allocation has been made.

sbatch_wait_nodes

If defined, the sbatch script will wait until all allocated nodes are ready for use (i.e. booted) before the initiation. By default, the sbatch script will be initiated as soon as the first node in the job allocation is ready. The sbatch command can use the --wait-all-nodes option to override this configuration parameter.

sched_interval=#

How frequently, in seconds, the main scheduling loop will execute and test all pending jobs. The default value is 60 seconds.

sched_max_job_start=#

The maximum number of jobs that the main scheduling logic will start in any single execution. The default value is zero, which imposes no limit.

sched_min_interval=#

How frequently, in microseconds, the main scheduling loop will execute and test any pending jobs. The scheduler runs in a limited fashion every time that any event happens which could enable a job to start (e.g. job submit, job terminate, etc.). If these events happen at a high frequency, the scheduler can run very frequently and consume significant resources if not throttled by this option. This option specifies the minimum time between the end of one scheduling cycle and the beginning of the next scheduling cycle. A value of zero will disable throttling of the scheduling logic interval. The default value is 1,000,000 microseconds on Cray/ALPS systems and 2 microseconds on other systems.

spec_cores_first

Specialized cores will be selected from the first cores of the first sockets, cycling through the sockets on a round robin basis. By default, specialized cores will be selected from the last cores of the last sockets, cycling through the sockets on a round robin basis.

step_retry_count=#

When a step completes and there are steps ending resource allocation, then retry step allocations for at least this number of pending steps. Also see step_retry_time. The default value is 8 steps.

step_retry_time=#

When a step completes and there are steps ending resource allocation, then retry step allocations for all steps which have been pending for at least this number of seconds. Also see step_retry_count. The default value is 60 seconds.

whole_pack

Requests to cancel, hold or release any component of a heterogeneous job will be applied to all components of the job.

Identifies the type of scheduler to be used. Note the slurmctld daemon must be restarted for a change in scheduler type to become effective (reconfiguring a running daemon has no effect for this parameter). The scontrol command can be used to manually change job priorities if desired. Acceptable values include:

sched/backfill

For a backfill scheduling module to augment the default FIFO scheduling. Backfill scheduling will initiate lower-priority jobs if doing so does not delay the expected initiation time of any higher priority job. Effectiveness of backfill scheduling is dependent upon users specifying job time limits, otherwise all jobs will have the same time limit and backfilling is impossible. Note documentation for the SchedulerParameters option above. This is the default configuration.

sched/builtin

This is the FIFO scheduler which initiates jobs in priority order. If any job in the partition can not be scheduled, no lower priority job in that partition will be scheduled. An exception is made for jobs that can not run due to partition constraints (e.g. the time limit) or down/drained nodes. In that case, lower priority jobs can be initiated and not impact the higher priority job.

sched/hold

To hold all newly arriving jobs if a file "/etc/slurm.hold" exists otherwise use the built-in FIFO scheduler

Identifies the type of resource selection algorithm to be used. Changing this value can only be done by restarting the slurmctld daemon and will result in the loss of all job information (running and pending) since the job state save format used by each plugin is different. Acceptable values include

select/bluegene

for a three-dimensional BlueGene system. The default value is "select/bluegene" for BlueGene systems.

select/cons_res

The resources within a node are individually allocated as consumable resources. Note that whole nodes can be allocated to jobs for selected partitions by using the OverSubscribe=Exclusive option. See the partition OverSubscribe parameter for more information.

select/cray

for a Cray system. The default value is "select/cray" for all Cray systems.

select/linear

for allocation of entire nodes assuming a one-dimensional array of nodes in which sequentially ordered nodes are preferable. For a heterogeneous cluster (e.g. different CPU counts on the various nodes), resource allocations will favor nodes with high CPU counts as needed based upon the job's node and CPU specification if TopologyPlugin=topology/none is configured. Use of other topology plugins with select/linear and heterogeneous nodes is not recommended and may result in valid job allocation requests being rejected. This is the default value for non-BlueGene systems.

select/serial

for allocating resources to single CPU jobs only. Highly optimized for maximum throughput. NOTE: SPANK environment variables are NOT propagated to the job's Epilog program.

The permitted values of SelectTypeParameters depend upon the configured value of SelectType. SelectType=select/bluegene supports no SelectTypeParameters. The only supported options for SelectType=select/linear are CR_ONE_TASK_PER_CORE and CR_Memory, which treats memory as a consumable resource and prevents memory over subscription with job preemption or gang scheduling. By default SelectType=select/linear allocates whole nodes to jobs without considering their memory consumption. By default SelectType=select/cons_res, SelectType=select/cray, and SelectType=select/serial use CR_CPU, which allocates CPU to jobs without considering their memory consumption.

The following options are supported for SelectType=select/cray:

OTHER_CONS_RES

Layer the select/cons_res plugin under the select/cray plugin, the default is to layer on select/linear. This also allows all the options for SelectType=select/cons_res.

NHC_ABSOLUTELY_NO

Never run the node health check. Implies NHC_NO and NHC_NO_STEPS as well.

NHC_NO_STEPS

Do not run the node health check after each step. Default is to run after each step.

NHC_NO

Do not run the node health check after each allocation. Default is to run after each allocation. This also sets NHC_NO_STEPS, so the NHC will never run except when nodes have been left with unkillable steps.

The following options are supported for SelectType=select/cons_res:

CR_CPU

CPUs are consumable resources. Configure the number of CPUs on each node, which may be equal to the count of cores or hyper-threads on the node depending upon the desired minimum resource allocation. The node's Boards, Sockets, CoresPerSocket and ThreadsPerCore may optionally be configured and result in job allocations which have improved locality; however doing so will prevent more than one job being from being allocated on each core.

CR_CPU_Memory

CPUs and memory are consumable resources. Configure the number of CPUs on each node, which may be equal to the count of cores or hyper-threads on the node depending upon the desired minimum resource allocation. The node's Boards, Sockets, CoresPerSocket and ThreadsPerCore may optionally be configured and result in job allocations which have improved locality; however doing so will prevent more than one job being from being allocated on each core. Setting a value for DefMemPerCPU is strongly recommended.

CR_Core

Cores are consumable resources. On nodes with hyper-threads, each thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not allocated threads on the same core. The count of CPUs allocated to a job may be rounded up to account for every CPU on an allocated core.

CR_Core_Memory

Cores and memory are consumable resources. On nodes with hyper-threads, each thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not allocated threads on the same core. The count of CPUs allocated to a job may be rounded up to account for every CPU on an allocated core. Setting a value for DefMemPerCPU is strongly recommended.

CR_ONE_TASK_PER_CORE

Allocate one task per core by default. Without this option, by default one task will be allocated per thread on nodes with more than one ThreadsPerCore configured. NOTE: This option cannot be used with CR_CPU*.

CR_CORE_DEFAULT_DIST_BLOCK

Allocate cores within a node using block distribution by default. This is a pseudo-best-fit algorithm that minimizes the number of boards and minimizes the number of sockets (within minimum boards) used for the allocation. This default behavior can be overridden specifying a particular "-m" parameter with srun/salloc/sbatch. Without this option, cores will be allocated cyclicly across the sockets.

CR_LLN

Schedule resources to jobs on the least loaded nodes (based upon the number of idle CPUs). This is generally only recommended for an environment with serial jobs as idle resources will tend to be highly fragmented, resulting in parallel jobs being distributed across many nodes. Note that node Weight takes precedence over how many idle resources are on each node. Also see the partition configuration parameter LLN use the least loaded nodes in selected partitions.

CR_Pack_Nodes

If a job allocation contains more resources than will be used for launching tasks (e.g. if whole nodes are allocated to a job), then rather than distributing a job's tasks evenly across it's allocated nodes, pack them as tightly as possible on these nodes. For example, consider a job allocation containing two entire nodes with eight CPUs each. If the job starts ten tasks across those two nodes without this option, it will start five tasks on each of the two nodes. With this option, eight tasks will be started on the first node and two tasks on the second node.

CR_Socket

Sockets are consumable resources. On nodes with multiple cores, each core or thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not allocated resources on the same socket.

CR_Socket_Memory

Memory and sockets are consumable resources. On nodes with multiple cores, each core or thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not allocated resources on the same socket. Setting a value for DefMemPerCPU is strongly recommended.

CR_Memory

Memory is a consumable resource. NOTE: This implies OverSubscribe=YES or OverSubscribe=FORCE for all partitions. Setting a value for DefMemPerCPU is strongly recommended.

The name of the user that the slurmctld daemon executes as. For security purposes, a user other than "root" is recommended. This user must exist on all nodes of the cluster for authentication of communications between Slurm components. The default value is "root".

The level of detail to provide slurmctld daemon's logs. The default value is info. If the slurmctld daemon is initiated with -v or --verbose options, that debug level will be preserve or restored upon reconfiguration.

quiet

Log nothing

fatal

Log only fatal errors

error

Log only errors

info

Log errors and general informational messages

verbose

Log errors and verbose informational messages

debug

Log errors and verbose informational messages and debugging messages

debug2

Log errors and verbose informational messages and more debugging messages

debug3

Log errors and verbose informational messages and even more debugging messages

debug4

Log errors and verbose informational messages and even more debugging messages

debug5

Log errors and verbose informational messages and even more debugging messages

The port number that the Slurm controller, slurmctld, listens to for work. The default value is SLURMCTLD_PORT as established at system build time. If none is explicitly specified, it will be set to 6817. SlurmctldPort may also be configured to support a range of port numbers in order to accept larger bursts of incoming messages by specifying two numbers separated by a dash (e.g. SlurmctldPort=6817-6818). NOTE: Either slurmctld and slurmd daemons must not execute on the same nodes or the values of SlurmctldPort and SlurmdPort must be different.

Note: On Cray systems, Realm-Specific IP Addressing (RSIP) will automatically try to interact with anything opened on ports 8192-60000. Configure SlurmctldPort to use a port outside of the configured SrunPortRange and RSIP's port range.

The slurmctld daemon will log events to the syslog file at the specified level of detail (the SlurmctldLogFile file will include log messages at the level of details specified by the SlurmctldDebug configuration parameter). If the slurmctld daemon is run in the foreground (started with the -D command line option) the SlurmctldSyslogDebug configuration parameter will be ignored. The default value is quiet unless there is no configured SlurmctldLogFile, in which case the default value will be fatal so that fatal errors are logged somewhere.

quiet

Log nothing

fatal

Log only fatal errors

error

Log only errors

info

Log errors and general informational messages

verbose

Log errors and verbose informational messages

debug

Log errors and verbose informational messages and debugging messages

debug2

Log errors and verbose informational messages and more debugging messages

debug3

Log errors and verbose informational messages and even more debugging messages

debug4

Log errors and verbose informational messages and even more debugging messages

debug5

Log errors and verbose informational messages and even more debugging messages

Fully qualified pathname of a file into which the slurmd daemon's logs are written. The default value is none (performs logging via syslog). Any "%h" within the name is replaced with the hostname on which the slurmd is running. Any "%n" within the name is replaced with the Slurm node name on which the slurmd is running.See the section Logging if a pathname is specified.

Fully qualified pathname of a file into which the slurmd daemon may write its process id. This may be used for automated signal processing. Any "%h" within the name is replaced with the hostname on which the slurmd is running. Any "%n" within the name is replaced with the Slurm node name on which the slurmd is running. The default value is "/var/run/slurmd.pid".

The port number that the Slurm compute node daemon, slurmd, listens to for work. The default value is SLURMD_PORT as established at system build time. If none is explicitly specified, its value will be 6818. NOTE: Either slurmctld and slurmd daemons must not execute on the same nodes or the values of SlurmctldPort and SlurmdPort must be different.

Note: On Cray systems, Realm-Specific IP Addressing (RSIP) will automatically try to interact with anything opened on ports 8192-60000. Configure SlurmdPort to use a port outside of the configured SrunPortRange and RSIP's port range.

Fully qualified pathname of a directory into which the slurmd daemon's state information and batch job script information are written. This must be a common pathname for all nodes, but should represent a directory which is local to each node (reference a local file system). The default value is "/var/spool/slurmd". Any "%h" within the name is replaced with the hostname on which the slurmd is running. Any "%n" within the name is replaced with the Slurm node name on which the slurmd is running.

The slurmd daemon will log events to the syslog file at the specified level of detail (the SlurmdLogFile file will include log messages at the level of details specified by the SlurmdDebug configuration parameter). If the slurmd daemon is run in the foreground (started with the -D command line option) the SlurmdSyslogDebug configuration parameter will be ignored. The default value is quiet unless there is no configured SlurmdLogFile, in which case the default value will be fatalso that fatal errors are logged somewhere.

quiet

Log nothing

fatal

Log only fatal errors

error

Log only errors

info

Log errors and general informational messages

verbose

Log errors and verbose informational messages

debug

Log errors and verbose informational messages and debugging messages

debug2

Log errors and verbose informational messages and more debugging messages

debug3

Log errors and verbose informational messages and even more debugging messages

debug4

Log errors and verbose informational messages and even more debugging messages

debug5

Log errors and verbose informational messages and even more debugging messages

The interval, in seconds, that the Slurm controller waits for slurmd to respond before configuring that node's state to DOWN. A value of zero indicates the node will not be tested by slurmctld to confirm the state of slurmd, the node will not be automatically set to a DOWN state indicating a non-responsive slurmd, and some other tool will take responsibility for monitoring the state of each compute node and its slurmd daemon. Slurm's hierarchical communication mechanism is used to ping the slurmd daemons in order to minimize system noise and overhead. The default value is 300 seconds. The value may not exceed 65533 seconds.

Fully qualified pathname of the scheduling event logging file. The syntax of this parameter is the same as for SlurmctldLogFile. In order to configure scheduler logging, set both the SlurmSchedLogFile and SlurmSchedLogLevel parameters.

The initial level of scheduling event logging, similar to the SlurmctldDebug parameter used to control the initial level of slurmctld logging. Valid values for SlurmSchedLogLevel are "0" (scheduler logging disabled) and "1" (scheduler logging enabled). If this parameter is omitted, the value defaults to "0" (disabled). In order to configure scheduler logging, set both the SlurmSchedLogFile and SlurmSchedLogLevel parameters. The scheduler logging level can be changed dynamically using scontrol.

Fully qualified pathname of an executable to be run by srun following the completion of a job step. The command line arguments for the executable will be the command and arguments of the job step. This configuration parameter may be overridden by srun's --epilog parameter. Note that while the other "Epilog" executables (e.g., TaskEpilog) are run by slurmd on the compute nodes where the tasks are executed, the SrunEpilog runs on the node where the "srun" is executing.

The srun creates a set of listening ports to communicate with the controller, the slurmstepd and to handle the application I/O. By default these ports are ephemeral meaning the port numbers are selected by the kernel. Using this parameter allow sites to configure a range of ports from which srun ports will be selected. This is useful if sites want to allow only certain port range on their network.

Note: On Cray systems, Realm-Specific IP Addressing (RSIP) will automatically try to interact with anything opened on ports 8192-60000. Configure SrunPortRange to use a range of ports above those used by RSIP, ideally 1000 or more ports, for example "SrunPortRange=60001-63000".

Note: A sufficient number of ports must be configured based on the estimated number of srun on the submission nodes considering that srun opens 3 listening ports plus 2 more for every 48 hosts. Example:

Fully qualified pathname of an executable to be run by srun prior to the launch of a job step. The command line arguments for the executable will be the command and arguments of the job step. This configuration parameter may be overridden by srun's --prolog parameter. Note that while the other "Prolog" executables (e.g., TaskProlog) are run by slurmd on the compute nodes where the tasks are executed, the SrunProlog runs on the node where the "srun" is executing.

Fully qualified pathname of a directory into which the Slurm controller, slurmctld, saves its state (e.g. "/usr/local/slurm/checkpoint"). Slurm state will saved here to recover from system failures. SlurmUser must be able to create files in this directory. If you have a BackupController configured, this location should be readable and writable by both systems. Since all running and pending job information is stored here, the use of a reliable file system (e.g. RAID) is recommended. The default value is "/var/spool". If any slurm daemons terminate abnormally, their core files will also be written into this directory.

Specifies the nodes which are to not be placed in power save mode, even if the node remains idle for an extended period of time. Use Slurm's hostlist expression to identify nodes with an optional ":" separator and count of nodes to exclude from the preceeding range. For example "nid[10-20]:4" will prevent 4 usable nodes (i.e IDLE and not DOWN, DRAINING or already powered down) in the set "nid[10-20]" from being powered down. Multiple sets of nodes can be specified with or without counts in a comma separated list (e.g "nid[10-20]:4,nid[80-90]:2"). If a node count specification is given, any list of nodes to NOT have a node count must be after the last specification with a count. For example "nid[10-20]:4,nid[60-70]" will exclude 4 nodes in the set "nid[10-20]:4" plus all nodes in the set "nid[60-70]" while "nid[1-3],nid[10-20]:4" will exclude 4 nodes from the set "nid[1-3],nid[10-20]". By default no nodes are excluded. Related configuration options include ResumeTimeout, ResumeProgram, ResumeRate, SuspendProgram, SuspendRate, SuspendTime, SuspendTimeout, and SuspendExcParts.

Specifies the partitions whose nodes are to not be placed in power save mode, even if the node remains idle for an extended period of time. Multiple partitions can be identified and separated by commas. By default no nodes are excluded. Related configuration options include ResumeTimeout, ResumeProgram, ResumeRate, SuspendProgram, SuspendRate, SuspendTime SuspendTimeout, and SuspendExcNodes.

SuspendProgram is the program that will be executed when a node remains idle for an extended period of time. This program is expected to place the node into some power save mode. This can be used to reduce the frequency and voltage of a node or completely power the node off. The program executes as SlurmUser. The argument to the program will be the names of nodes to be placed into power savings mode (using Slurm's hostlist expression format). By default, no program is run. Related configuration options include ResumeTimeout, ResumeProgram, ResumeRate, SuspendRate, SuspendTime, SuspendTimeout, SuspendExcNodes, and SuspendExcParts.

The rate at which nodes are place into power save mode by SuspendProgram. The value is number of nodes per minute and it can be used to prevent a large drop in power consumption (e.g. after a large job completes). A value of zero results in no limits being imposed. The default value is 60 nodes per minute. Related configuration options include ResumeTimeout, ResumeProgram, ResumeRate, SuspendProgram, SuspendTime, SuspendTimeout, SuspendExcNodes, and SuspendExcParts.

Nodes which remain idle for this number of seconds will be placed into power save mode by SuspendProgram. For efficient system utilization, it is recommended that the value of SuspendTime be at least as large as the sum of SuspendTimeout plus ResumeTimeout. A value of -1 disables power save mode and is the default. Related configuration options include ResumeTimeout, ResumeProgram, ResumeRate, SuspendProgram, SuspendRate, SuspendTimeout, SuspendExcNodes, and SuspendExcParts.

Maximum time permitted (in seconds) between when a node suspend request is issued and when the node is shutdown. At that time the node must be ready for a resume request to be issued as needed for new work. The default value is 30 seconds. Related configuration options include ResumeProgram, ResumeRate, ResumeTimeout, SuspendRate, SuspendTime, SuspendProgram, SuspendExcNodes and SuspendExcParts. More information is available at the Slurm web site ( https://slurm.schedmd.com/power_save.html ).

Identifies the type of switch or interconnect used for application communications. Acceptable values include "switch/cray" for Cray systems, "switch/none" for switches not requiring special processing for job launch or termination (Ethernet, and InfiniBand) and "switch/nrt" for IBM's Network Resource Table API. The default value is "switch/none". All Slurm daemons, commands and running jobs must be restarted for a change in SwitchType to take effect. If running jobs exist at the time slurmctld is restarted with a new value of SwitchType, records of all jobs in any state may be lost.

Identifies the type of task launch plugin, typically used to provide resource management within a node (e.g. pinning tasks to specific processors). More than one task plugin can be specified in a comma separated list. The prefix of "task/" is optional. Acceptable values include:

task/affinity

enables resource containment using CPUSETs. This enables the --cpu-bind and/or --mem-bind srun options. If you use "task/affinity" and encounter problems, it may be due to the variety of system calls used to implement task affinity on different operating systems.

for systems requiring no special handling of user tasks. Lacks support for the --cpu-bind and/or --mem-bind srun options. The default value is "task/none".

NOTE: It is recommended to stack task/affinity,task/cgroup together when configuring TaskPlugin, and setting TaskAffinity=no and ConstrainCores=yes in cgroup.conf. This setup uses the task/affinity plugin for setting the affinity of the tasks (which is better and different than task/cgroup) and uses the task/cgroup plugin to fence tasks into the specified resources, thus combining the best of both pieces.

NOTE: For CRAY systems only: task/cgroup must be used with, and listed after task/cray in TaskPlugin. The task/affinity plugin can be listed everywhere, but the previous constrain must be satisfied. So for CRAY systems, a configuration like this is recommended:

Optional parameters for the task plugin. Multiple options should be comma separated. If None, Boards, Sockets, Cores, Threads, and/or Verbose are specified, they will override the --cpu-bind option specified by the user in the srun command. None, Boards, Sockets, Cores and Threads are mutually exclusive and since they decrease scheduling flexibility are not generally recommended (select no more than one of them). Cpusets and Sched are mutually exclusive (select only one of them). All TaskPluginParam options are supported on FreeBSD except Cpusets. The Sched option uses cpuset_setaffinity() on FreeBSD, not sched_setaffinity().

If specialized cores or CPUs are identified for the node (i.e. the CoreSpecCount or CpuSpecList are configured for the node), then Slurm daemons running on the compute node (i.e. slurmd and slurmstepd) should run outside of those resources (i.e. specialized resources are completely unavailable to Slurm daemons and jobs spawned by Slurm). This option may not be used with the task/cray plugin.

Verbose

Verbosely report binding before tasks run. Overrides user options.

Autobind

Set a default binding in the event that "auto binding" doesn't find a match. Set to Threads, Cores or Sockets (E.g. TaskPluginParam=autobind=threads).

Fully qualified pathname of a program to be execute as the slurm job's owner prior to initiation of each task. Besides the normal environment variables, this has SLURM_TASK_PID available to identify the process ID of the task being started. Standard output from this program can be used to control the environment variables and output for the user program.

export NAME=value

Will set environment variables for the task being spawned. Everything after the equal sign to the end of the line will be used as the value for the environment variable. Exporting of functions is not currently supported.

print ...

Will cause that line (without the leading "print ") to be printed to the job's standard output.

Used to directly bind to the address of what the node resolves to running the slurmctld instead of binding messages to any address on the node, which is the default.

NoInAddrAny

Used to directly bind to the address of what the node resolves to instead of binding messages to any address on the node which is the default. This option is for all daemons/clients except for the slurmctld.

TopoOptional

Only optimize allocation for network topology if the job includes a switch option. Since optimizing resource allocation for topology involves much higher system overhead, this option can be used to impose the extra overhead only on jobs which can take advantage of it. If most job allocations are not optimized for network topology, they make fragment resources to the point that topology optimization for other jobs will be difficult to achieve. NOTE: Jobs may span across nodes without common parent switches with this enabled.

Identifies the plugin to be used for determining the network topology and optimizing job allocations to minimize network contention. See Network Topology below for details. Additional plugins may be provided in the future which gather topology information directly from the network. Acceptable values include:

topology/3d_torus

best-fit logic over three-dimensional topology

topology/node_rank

orders nodes based upon information a node_rank field in the node record as generated by a select plugin. Slurm performs a best-fit algorithm over those ordered nodes

topology/none

default for other systems, best-fit logic over one-dimensional topology

Boolean yes or no. Used to set display and track of the Workload Characterization Key. Must be set to track correct wckey usage. NOTE: You must also set TrackWCKey in your slurmdbd.conf file to create historical usage reports.

Slurmd daemons use a virtual tree network for communications. TreeWidth specifies the width of the tree (i.e. the fanout). On architectures with a front end node running the slurmd daemon, the value must always be equal to or greater than the number of front end nodes which eliminates the need for message forwarding between the slurmd daemons. On other architectures the default value is 50, meaning each slurmd daemon can communicate with up to 50 other slurmd daemons and over 2500 nodes can be contacted with two message hops. The default value will work well for most clusters. Optimal system performance can typically be achieved if TreeWidth is set to the square root of the number of nodes in the cluster for systems having no more than 2500 nodes or the cube root for larger systems. The value may not exceed 65533.

If the processes in a job step are determined to be unkillable for a period of time specified by the UnkillableStepTimeout variable, the program specified by UnkillableStepProgram will be executed. This program can be used to take special actions to clean up the unkillable processes and/or notify computer administrators. The program will be run SlurmdUser (usually "root") on the compute node. By default no program is run.

The length of time, in seconds, that Slurm will wait before deciding that processes in a job step are unkillable (after they have been signaled with SIGKILL) and execute UnkillableStepProgram as described above. The default timeout value is 60 seconds. If exceeded, the compute node will be drained to prevent future jobs from being scheduled on the node.

If set to 1, PAM (Pluggable Authentication Modules for Linux) will be enabled. PAM is used to establish the upper bounds for resource limits. With PAM support enabled, local system administrators can dynamically configure system resource limits. Changing the upper bound of a resource limit will not alter the limits of running jobs, only jobs started after a change has been made will pick up the new limits. The default value is 0 (not to enable PAM support). Remember that PAM also needs to be configured to support Slurm as a service. For sites using PAM's directory based configuration option, a configuration file named slurm should be created. The module-type, control-flags, and module-path names that should be included in the file are:auth required pam_localuser.soauth required pam_shells.soaccount required pam_unix.soaccount required pam_access.sosession required pam_unix.soFor sites configuring PAM with a general configuration file, the appropriate lines (see above), where slurm is the service-name, should be added.

NOTE: UsePAM option has nothing to do with the contribs/pam/pam_slurm and/or contribs/pam_slurm_adopt modules. So these two modules can work independently of the value set for UsePAM.

Memory specifications in job requests apply to real memory size (also known as resident set size). It is possible to enforce virtual memory limits for both jobs and job steps by limiting their virtual memory to some percentage of their real memory allocation. The VSizeFactor parameter specifies the job's or job step's virtual memory limit as a percentage of its real memory limit. For example, if a job's real memory limit is 500MB and VSizeFactor is set to 101 then the job will be killed if its real memory exceeds 500MB or its virtual memory exceeds 505MB (101 percent of the real memory limit). The default value is 0, which disables enforcement of virtual memory limits. The value may not exceed 65533 percent.

Specifies how many seconds the srun command should by default wait after the first task terminates before terminating all remaining tasks. The "--wait" option on the srun command line overrides this value. The default value is 0, which disables this feature. May not exceed 65533 seconds.

The configuration of nodes (or machines) to be managed by Slurm is also specified in /etc/slurm.conf. Changes in node configuration (e.g. adding nodes, changing their processor count, etc.) require restarting both the slurmctld daemon and the slurmd daemons. All slurmd daemons must know each node in the system to forward messages in support of hierarchical communications. Only the NodeName must be supplied in the configuration file. All other node configuration information is optional. It is advisable to establish baseline node configurations, especially if the cluster is heterogeneous. Nodes which register to the system with less than the configured resources (e.g. too little memory), will be placed in the "DOWN" state to avoid scheduling jobs on them. Establishing baseline configurations will also speed Slurm's scheduling process by permitting it to compare job requirements against these (relatively few) configuration parameters and possibly avoid having to check job requirements against every individual node's configuration. The resources checked at node registration time are: CPUs, RealMemory and TmpDisk. While baseline values for each of these can be established in the configuration file, the actual values upon node registration are recorded and these actual values may be used for scheduling purposes (depending upon the value of FastSchedule in the configuration file.

Default values can be specified with a record in which NodeName is "DEFAULT". The default entry values will apply only to lines following it in the configuration file and the default values can be reset multiple times in the configuration file with multiple entries where "NodeName=DEFAULT". Each line where NodeName is "DEFAULT" will replace or add to previous default values and not a reinitialize the default values. The "NodeName=" specification must be placed on every line describing the configuration of nodes. A single node name can not appear as a NodeName value in more than one line (duplicate node name records will be ignored). In fact, it is generally possible and desirable to define the configurations of all nodes in only a few lines. This convention permits significant optimization in the scheduling of larger clusters. In order to support the concept of jobs requiring consecutive nodes on some architectures, node specifications should be place in this file in consecutive order. No single node name may be listed more than once in the configuration file. Use "DownNodes=" to record the state of nodes which are temporarily in a DOWN, DRAIN or FAILING state without altering permanent configuration information. A job step's tasks are allocated to nodes in order the nodes appear in the configuration file. There is presently no capability within Slurm to arbitrarily order a job step's tasks.

Multiple node names may be comma separated (e.g. "alpha,beta,gamma") and/or a simple node range expression may optionally be used to specify numeric ranges of nodes to avoid building a configuration file with large numbers of entries. The node range expression can contain one pair of square brackets with a sequence of comma separated numbers and/or ranges of numbers separated by a "-" (e.g. "linux[0-64,128]", or "lx[15,18,32-33]"). Note that the numeric ranges can include one or more leading zeros to indicate the numeric portion has a fixed number of digits (e.g. "linux[0000-1023]"). Multiple numeric ranges can be included in the expression (e.g. "rack[0-63]_blade[0-41]"). If one or more numeric expressions are included, one of them must be at the end of the name (e.g. "unit[0-31]rack" is invalid), but arbitrary names can always be used in a comma separated list.

On BlueGene systems only, the square brackets should contain pairs of three digit numbers separated by a "x". These numbers indicate the boundaries of a rectangular prism (e.g. "bgl[000x144,400x544]"). See BlueGene documentation for more details. The node configuration specified the following information:

Name that Slurm uses to refer to a node (or base partition for BlueGene systems). Typically this would be the string that "/bin/hostname -s" returns. It may also be the fully qualified domain name as returned by "/bin/hostname -f" (e.g. "foo1.bar.com"), or any valid domain name associated with the host through the host database (/etc/hosts) or DNS, depending on the resolver settings. Note that if the short form of the hostname is not used, it may prevent use of hostlist expressions (the numeric portion in brackets must be at the end of the string). Only short hostname forms are compatible with the switch/nrt plugin at this time. It may also be an arbitrary string if NodeHostname is specified. If the NodeName is "DEFAULT", the values specified with that record will apply to subsequent node specifications unless explicitly set to other values in that node record or replaced with a different set of default values. Each line where NodeName is "DEFAULT" will replace or add to previous default values and not a reinitialize the default values. For architectures in which the node order is significant, nodes will be considered consecutive in the order defined. For example, if the configuration for "NodeName=charlie" immediately follows the configuration for "NodeName=baker" they will be considered adjacent in the computer.

Typically this would be the string that "/bin/hostname -s" returns. It may also be the fully qualified domain name as returned by "/bin/hostname -f" (e.g. "foo1.bar.com"), or any valid domain name associated with the host through the host database (/etc/hosts) or DNS, depending on the resolver settings. Note that if the short form of the hostname is not used, it may prevent use of hostlist expressions (the numeric portion in brackets must be at the end of the string). Only short hostname forms are compatible with the switch/nrt plugin at this time. A node range expression can be used to specify a set of nodes. If an expression is used, the number of nodes identified by NodeHostname on a line in the configuration file must be identical to the number of nodes identified by NodeName. By default, the NodeHostname will be identical in value to NodeName.

Name that a node should be referred to in establishing a communications path. This name will be used as an argument to the gethostbyname() function for identification. If a node range expression is used to designate multiple nodes, they must exactly match the entries in the NodeName (e.g. "NodeName=lx[0-7] NodeAddr=elx[0-7]"). NodeAddr may also contain IP addresses. By default, the NodeAddr will be identical in value to NodeHostname.

Number of Baseboards in nodes with a baseboard controller. Note that when Boards is specified, SocketsPerBoard, CoresPerSocket, and ThreadsPerCore should be specified. Boards and CPUs are mutually exclusive. The default value is 1.

Number of cores reserved for system use. These cores will not be available for allocation to user jobs. Depending upon the TaskPluginParameter option of SlurmOffSpec, Slurm daemons (i.e. slurmd and slurmstepd) may either be confined to these resources (the default) or prevented from using these resources. Isolation of the Slurm daemons from user jobs may improve application performance. If this option and CpuSpecList are both designated for a node, an error is generated. For information on the algorithm used by Slurm to select the cores refer to the core specialization documentation (https://slurm.schedmd.com/core_spec.html).

Number of cores in a single physical processor socket (e.g. "2"). The CoresPerSocket value describes physical cores, not the logical number of processors per socket. NOTE: If you have multi-core processors, you will likely need to specify this parameter in order to optimize scheduling. The default value is 1.

Number of logical processors on the node (e.g. "2"). CPUs and Boards are mutually exclusive. It can be set to the total number of sockets, cores or threads. This can be useful when you want to schedule only the cores on a hyper-threaded node. If CPUs is omitted, it will be set equal to the product of Sockets, CoresPerSocket, and ThreadsPerCore. The default value is 1.

A comma delimited list of Slurm abstract CPU IDs reserved for system use. The list will be expanded to include all other CPUs, if any, on the same cores. These cores will not be available for allocation to user jobs. Depending upon the TaskPluginParameter option of SlurmOffSpec, Slurm daemons (i.e. slurmd and slurmstepd) may either be confined to these resources (the default) or prevented from using these resources. Isolation of the Slurm daemons from user jobs may improve application performance. If this option and CoreSpecCount are both designated for a node, an error is generated. This option has no effect unless cgroup job confinement is also configured (TaskPlugin=task/cgroup with ConstrainCores=yes in cgroup.conf).

A comma delimited list of arbitrary strings indicative of some characteristic associated with the node. There is no value associated with a feature at this time, a node either has a feature or it does not. If desired a feature may contain a numeric component indicating, for example, processor speed. By default a node has no features. Also see Gres.

A comma delimited list of generic resources specifications for a node. The format is: "<name>[:<type>][:no_consume]:<number>[K|M|G]". The first field is the resource name, which matches the GresType configuration parameter name. The optional type field might be used to identify a model of that generic resource. A generic resource can also be specified as non-consumable (i.e. multiple jobs can use the same generic resource) with the optional field ":no_consume". The final field must specify a generic resources count. A suffix of "K", "M", "G", "T" or "P" may be used to multiply the number by 1024, 1048576, 1073741824, etc. respectively. (e.g."Gres=gpu:tesla:1,gpu:kepler:1,bandwidth:lustre:no_consume:4G"). By default a node has no generic resources and its maximum count is that of an unsigned 64bit integer. Also see Feature.

Amount of memory, in megabytes, reserved for system use and not available for user allocations. If the task/cgroup plugin is configured and that plugin constrains memory allocations (i.e. TaskPlugin=task/cgroup in slurm.conf, plus ConstrainRAMSpace=yes in cgroup.conf), then Slurm compute node daemons (slurmd plus slurmstepd) will be allocated the specified memory limit. Note that having the Memory set in SelectTypeParameters as any of the options that has it as a consumable resource is needed for this option to work. The daemons will not be killed if they exhaust the memory allocation (ie. the Out-Of-Memory Killer is disabled for the daemon's memory cgroup). If the task/cgroup plugin is not configured, the specified memory will only be unavailable for user allocations.

The port number that the Slurm compute node daemon, slurmd, listens to for work on this particular node. By default there is a single port number for all slurmd daemons on all compute nodes as defined by the SlurmdPort configuration parameter. Use of this option is not generally recommended except for development or testing purposes. If multiple slurmd daemons execute on a node this can specify a range of ports.

Note: On Cray systems, Realm-Specific IP Addressing (RSIP) will automatically try to interact with anything opened on ports 8192-60000. Configure Port to use a port outside of the configured SrunPortRange and RSIP's port range.

Size of real memory on the node in megabytes (e.g. "2048"). The default value is 1. Lowering RealMemory with the goal of setting aside some amount for the OS and not available for job allocations will not work as intended if Memory is not set as a consumable resource in SelectTypeParameters. So one of the *_Memory options need to be enabled for that goal to be accomplished. Also see MemSpecLimit.

Number of physical processor sockets/chips on the node (e.g. "2"). If Sockets is omitted, it will be inferred from CPUs, CoresPerSocket, and ThreadsPerCore. NOTE: If you have multi-core processors, you will likely need to specify these parameters. Sockets and SocketsPerBoard are mutually exclusive. If Sockets is specified when Boards is also used, Sockets is interpreted as SocketsPerBoard rather than total sockets. The default value is 1.

State of the node with respect to the initiation of user jobs. Acceptable values are "CLOUD", "DOWN", "DRAIN", "FAIL", "FAILING", "FUTURE" and "UNKNOWN". Node states of "BUSY" and "IDLE" should not be specified in the node configuration, but set the node state to "UNKNOWN" instead. Setting the node state to "UNKNOWN" will result in the node state being set to "BUSY", "IDLE" or other appropriate state based upon recovered system state information. The default value is "UNKNOWN". Also see the DownNodes parameter below.

CLOUD

Indicates the node exists in the cloud. It's initial state will be treated as powered down. The node will be available for use after it's state is recovered from Slurm's state save file or the slurmd daemon starts on the compute node.

DOWN

Indicates the node failed and is unavailable to be allocated work.

DRAIN

Indicates the node is unavailable to be allocated work.on.

FAIL

Indicates the node is expected to fail soon, has no jobs allocated to it, and will not be allocated to any new jobs.

FAILING

Indicates the node is expected to fail soon, has one or more jobs allocated to it, but will not be allocated to any new jobs.

FUTURE

Indicates the node is defined for future use and need not exist when the Slurm daemons are started. These nodes can be made available for use simply by updating the node state using the scontrol command rather than restarting the slurmctld daemon. After these nodes are made available, change their State in the slurm.conf file. Until these nodes are made available, they will not be seen using any Slurm commands or nor will any attempt be made to contact them.

UNKNOWN

Indicates the node's state is undefined (BUSY or IDLE), but will be established when the slurmd daemon on that node registers. The default value is "UNKNOWN".

Number of logical threads in a single physical core (e.g. "2"). Note that the Slurm can allocate resources to jobs down to the resolution of a core. If your system is configured with more than one thread per core, execution of a different job on each thread is not supported unless you configure SelectTypeParameters=CR_CPU plus CPUs; do not configure Sockets, CoresPerSocket or ThreadsPerCore. A job can execute a one task per thread from within one job step or execute a distinct job step on each of the threads. Note also if you are running with more than 1 thread per core and running the select/cons_res plugin you will want to set the SelectTypeParameters variable to something other than CR_CPU to avoid unexpected results. The default value is 1.

Total size of temporary disk storage in TmpFS in megabytes (e.g. "16384"). TmpFS (for "Temporary File System") identifies the location which jobs should use for temporary storage. Note this does not indicate the amount of free space available to the user on the node, only the total file system size. The system administration should ensure this file system is purged as needed so that user jobs have access to most of this space. The Prolog and/or Epilog programs (specified in the configuration file) might be used to ensure the file system is kept clean. The default value is 0.

TRESWeights TRESWeights are used to calculate a value that represents how

busy a node is. Currently only used in federation configurations. TRESWeights are different from TRESBillingWeights -- which is used for fairshare calcuations.

TRES weights are specified as a comma-separated list of <TRES Type>=<TRES Weight> pairs.

e.g.
NodeName=node1 ... TRESWeights="CPU=1.0,Mem=0.25G,GRES/gpu=2.0"

By default the weighted TRES value is calculated as the sum of all node TRES types multiplied by their corresponding TRES weight.

If PriorityFlags=MAX_TRES is configured, the weighted TRES value is calculated as the MAX of individual node TRES' (e.g. cpus, mem, gres).

The priority of the node for scheduling purposes. All things being equal, jobs will be allocated the nodes with the lowest weight which satisfies their requirements. For example, a heterogeneous collection of nodes might be placed into a single partition for greater system utilization, responsiveness and capability. It would be preferable to allocate smaller memory nodes rather than larger memory nodes if either will satisfy a job's requirements. The units of weight are arbitrary, but larger weights should be assigned to nodes with more processors, memory, disk space, higher processor speed, etc. Note that if a job allocation request can not be satisfied using the nodes with the lowest weight, the set of nodes with the next lowest weight is added to the set of nodes under consideration for use (repeat as needed for higher weight values). If you absolutely want to minimize the number of higher weight nodes allocated to a job (at a cost of higher scheduling overhead), give each node a distinct Weight value and they will be added to the pool of nodes being considered for scheduling individually. The default value is 1.

The "DownNodes=" configuration permits you to mark certain nodes as in a DOWN, DRAIN, FAIL, or FAILING state without altering the permanent configuration information listed under a "NodeName=" specification.

State of the node with respect to the initiation of user jobs. Acceptable values are "DOWN", "DRAIN", "FAIL", "FAILING" and "UNKNOWN". Node states of "BUSY" and "IDLE" should not be specified in the node configuration, but set the node state to "UNKNOWN" instead. Setting the node state to "UNKNOWN" will result in the node state being set to "BUSY", "IDLE" or other appropriate state based upon recovered system state information. The default value is "UNKNOWN".

DOWN

Indicates the node failed and is unavailable to be allocated work.

DRAIN

Indicates the node is unavailable to be allocated work.on.

FAIL

Indicates the node is expected to fail soon, has no jobs allocated to it, and will not be allocated to any new jobs.

FAILING

Indicates the node is expected to fail soon, has one or more jobs allocated to it, but will not be allocated to any new jobs.

UNKNOWN

Indicates the node's state is undefined (BUSY or IDLE), but will be established when the slurmd daemon on that node registers. The default value is "UNKNOWN".

On computers where frontend nodes are used to execute batch scripts rather than compute nodes (BlueGene or Cray systems), one may configure one or more frontend nodes using the configuration parameters defined below. These options are very similar to those used in configuring compute nodes. These options may only be used on systems configured and built with the appropriate parameters (--have-front-end, --enable-bluegene-emulation) or a system determined to have the appropriate architecture by the configure script (BlueGene or Cray systems). The front end configuration specifies the following information:

Comma separated list of group names which may execute jobs on this front end node. By default, all groups may use this front end node. If at least one group associated with the user attempting to execute the job is in AllowGroups, he will be permitted to use this front end node. May not be used with the DenyGroups option.

Name that Slurm uses to refer to a frontend node. Typically this would be the string that "/bin/hostname -s" returns. It may also be the fully qualified domain name as returned by "/bin/hostname -f" (e.g. "foo1.bar.com"), or any valid domain name associated with the host through the host database (/etc/hosts) or DNS, depending on the resolver settings. Note that if the short form of the hostname is not used, it may prevent use of hostlist expressions (the numeric portion in brackets must be at the end of the string). If the FrontendName is "DEFAULT", the values specified with that record will apply to subsequent node specifications unless explicitly set to other values in that frontend node record or replaced with a different set of default values. Each line where FrontendName is "DEFAULT" will replace or add to previous default values and not a reinitialize the default values. Note that since the naming of front end nodes would typically not follow that of the compute nodes (e.g. lacking X, Y and Z coordinates found in the compute node naming scheme), each front end node name should be listed separately and without a hostlist expression (i.e. frontend00,frontend01" rather than "frontend[00-01]").</p>

Name that a frontend node should be referred to in establishing a communications path. This name will be used as an argument to the gethostbyname() function for identification. As with FrontendName, list the individual node addresses rather than using a hostlist expression. The number of FrontendAddr records per line must equal the number of FrontendName records per line (i.e. you can't map to node names to one address). FrontendAddr may also contain IP addresses. By default, the FrontendAddr will be identical in value to FrontendName.

The port number that the Slurm compute node daemon, slurmd, listens to for work on this particular frontend node. By default there is a single port number for all slurmd daemons on all frontend nodes as defined by the SlurmdPort configuration parameter. Use of this option is not generally recommended except for development or testing purposes.

Note: On Cray systems, Realm-Specific IP Addressing (RSIP) will automatically try to interact with anything opened on ports 8192-60000. Configure Port to use a port outside of the configured SrunPortRange and RSIP's port range.

State of the frontend node with respect to the initiation of user jobs. Acceptable values are "DOWN", "DRAIN", "FAIL", "FAILING" and "UNKNOWN". "DOWN" indicates the frontend node has failed and is unavailable to be allocated work. "DRAIN" indicates the frontend node is unavailable to be allocated work. "FAIL" indicates the frontend node is expected to fail soon, has no jobs allocated to it, and will not be allocated to any new jobs. "FAILING" indicates the frontend node is expected to fail soon, has one or more jobs allocated to it, but will not be allocated to any new jobs. "UNKNOWN" indicates the frontend node's state is undefined (BUSY or IDLE), but will be established when the slurmd daemon on that node registers. The default value is "UNKNOWN". Also see the DownNodes parameter below.

For example: "FrontendName=frontend[00-03] FrontendAddr=efrontend[00-03] State=UNKNOWN" is used to define four front end nodes for running slurmd daemons.

The partition configuration permits you to establish different job limits or access controls for various groups (or partitions) of nodes. Nodes may be in more than one partition, making partitions serve as general purpose queues. For example one may put the same set of nodes into two different partitions, each with different constraints (time limit, job sizes, groups allowed to use the partition, etc.). Jobs are allocated resources within a single partition. Default values can be specified with a record in which PartitionName is "DEFAULT". The default entry values will apply only to lines following it in the configuration file and the default values can be reset multiple times in the configuration file with multiple entries where "PartitionName=DEFAULT". The "PartitionName=" specification must be placed on every line describing the configuration of partitions. Each line where PartitionName is "DEFAULT" will replace or add to previous default values and not a reinitialize the default values. A single partition name can not appear as a PartitionName value in more than one line (duplicate partition name records will be ignored). If a partition that is in use is deleted from the configuration and slurm is restarted or reconfigured (scontrol reconfigure), jobs using the partition are canceled. NOTE: Put all parameters for each partition on a single line. Each line of partition configuration information should represent a different partition. The partition configuration file contains the following information:

Comma separated list of group names which may execute jobs in the partition. If at least one group associated with the user attempting to execute the job is in AllowGroups, he will be permitted to use this partition. Jobs executed as user root can use any partition without regard to the value of AllowGroups. If user root attempts to execute a job as another user (e.g. using srun's --uid option), this other user must be in one of groups identified by AllowGroups for the job to successfully execute. The default value is "ALL". When set, all partitions that a user does not have access will be hidden from display regardless of the settings used for PrivateData. NOTE: For performance reasons, Slurm maintains a list of user IDs allowed to use each partition and this is checked at job submission time. This list of user IDs is updated when the slurmctld daemon is restarted, reconfigured (e.g. "scontrol reconfig") or the partition's AllowGroups value is reset, even if is value is unchanged (e.g. "scontrol update PartitionName=name AllowGroups=group"). For a user's access to a partition to change, both his group membership must change and Slurm's internal user ID list must change using one of the methods described above.

Comma separated list of Qos which may execute jobs in the partition. Jobs executed as user root can use any partition without regard to the value of AllowQos. The default value is "ALL". NOTE: If AllowQos is used then DenyQos will not be enforced. Also refer to DenyQos.

Default real memory size available per allocated CPU in megabytes. Used to avoid over-subscribing memory and causing paging. DefMemPerCPU would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). If not set, the DefMemPerCPU value for the entire cluster will be used. Also see DefMemPerNode and MaxMemPerCPU. DefMemPerCPU and DefMemPerNode are mutually exclusive. NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

Default real memory size available per allocated node in megabytes. Used to avoid over-subscribing memory and causing paging. DefMemPerNode would generally be used if whole nodes are allocated to jobs (SelectType=select/linear) and resources are over-subscribed (OverSubscribe=yes or OverSubscribe=force). If not set, the DefMemPerNode value for the entire cluster will be used. Also see DefMemPerCPU and MaxMemPerNode. DefMemPerCPU and DefMemPerNode are mutually exclusive. NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

Comma separated list of accounts which may not execute jobs in the partition. By default, no accounts are denied access NOTE: If AllowAccounts is used then DenyAccounts will not be enforced. Also refer to AllowAccounts.

If set to "YES" then user root will be prevented from running any jobs on this partition. The default value will be the value of DisableRootJobs set outside of a partition specification (which is "NO", allowing user root to execute jobs).

If set to "YES" then nodes will be exclusively allocated to users. Multiple jobs may be run for the same user, but only one user can be active at a time. This capability is also available on a per-job basis by using the --exclusive=user option.

Specifies, in units of seconds, the preemption grace time to be extended to a job which has been selected for preemption. The default value is zero, no preemption grace time is allowed on this partition. Once a job has been selected for preemption, it's end time is set to the current time plus GraceTime. The job is immediately sent SIGCONT and SIGTERM signals in order to provide notification of its imminent termination. This is followed by the SIGCONT, SIGTERM and SIGKILL signal sequence upon reaching its new end time. (Meaningful only for PreemptMode=CANCEL)

Specifies if the partition and its jobs are to be hidden by default. Hidden partitions will by default not be reported by the Slurm APIs or commands. Possible values are "YES" and "NO". The default value is "NO". Note that partitions that a user lacks access to by virtue of the AllowGroups parameter will also be hidden by default.

Schedule resources to jobs on the least loaded nodes (based upon the number of idle CPUs). This is generally only recommended for an environment with serial jobs as idle resources will tend to be highly fragmented, resulting in parallel jobs being distributed across many nodes. Note that node Weight takes precedence over how many idle resources are on each node. Also see the SelectParameters configuration parameter CR_LLN to use the least loaded nodes in every partition.

Maximum number of CPUs on any node available to all jobs from this partition. This can be especially useful to schedule GPUs. For example a node can be associated with two Slurm partitions (e.g. "cpu" and "gpu") and the partition/queue "cpu" could be limited to only a subset of the node's CPUs, ensuring that one or more CPUs would be available to jobs in the "gpu" partition/queue.

Maximum real memory size available per allocated CPU in megabytes. Used to avoid over-subscribing memory and causing paging. MaxMemPerCPU would generally be used if individual processors are allocated to jobs (SelectType=select/cons_res). If not set, the MaxMemPerCPU value for the entire cluster will be used. Also see DefMemPerCPU and MaxMemPerNode. MaxMemPerCPU and MaxMemPerNode are mutually exclusive. NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

Maximum real memory size available per allocated node in megabytes. Used to avoid over-subscribing memory and causing paging. MaxMemPerNode would generally be used if whole nodes are allocated to jobs (SelectType=select/linear) and resources are over-subscribed (OverSubscribe=yes or OverSubscribe=force). If not set, the MaxMemPerNode value for the entire cluster will be used. Also see DefMemPerNode and MaxMemPerCPU. MaxMemPerCPU and MaxMemPerNode are mutually exclusive. NOTE: Enforcement of memory limits currently requires enabling of accounting, which samples memory use on a periodic basis (data need not be stored, just collected).

Maximum count of nodes which may be allocated to any single job. For BlueGene systems this will be a c-nodes count and will be converted to a midplane count with a reduction in resolution. The default value is "UNLIMITED", which is represented internally as -1. This limit does not apply to jobs executed by SlurmUser or user root.

Maximum run time limit for jobs. Format is minutes, minutes:seconds, hours:minutes:seconds, days-hours, days-hours:minutes, days-hours:minutes:seconds or "UNLIMITED". Time resolution is one minute and second values are rounded up to the next minute. This limit does not apply to jobs executed by SlurmUser or user root.

Minimum count of nodes which may be allocated to any single job. For BlueGene systems this will be a c-nodes count and will be converted to a midplane count with a reduction in resolution. The default value is 1. This limit does not apply to jobs executed by SlurmUser or user root.

Comma separated list of nodes (or base partitions for BlueGene systems) which are associated with this partition. Node names may be specified using the node range expression syntax described above. A blank list of nodes (i.e. "Nodes= ") can be used if one wants a partition to exist, but have no resources (possibly on a temporary basis). A value of "ALL" is mapped to all nodes configured in the cluster.

Controls the ability of the partition to execute more than one job at a time on each resource (node, socket or core depending upon the value of SelectTypeParameters). If resources are to be over-subscribed, avoiding memory over-subscription is very important. SelectTypeParameters should be configured to treat memory as a consumable resource and the --mem option should be used for job allocations. Sharing of resources is typically useful only when using gang scheduling (PreemptMode=suspend,gang). Possible values for OverSubscribe are "EXCLUSIVE", "FORCE", "YES", and "NO". Note that a value of "YES" or "FORCE" can negatively impact performance for systems with many thousands of running jobs. The default value is "NO". For more information see the following web pages:https://slurm.schedmd.com/cons_res.html,https://slurm.schedmd.com/cons_res_share.html,https://slurm.schedmd.com/gang_scheduling.html, andhttps://slurm.schedmd.com/preempt.html.

EXCLUSIVE

Allocates entire nodes to jobs even with select/cons_res configured. Jobs that run in partitions with "OverSubscribe=EXCLUSIVE" will have exclusive access to all allocated nodes.

FORCE

Makes all resources in the partition available for sharing without any means for users to disable it. May be followed with a colon and maximum number of jobs in running or suspended state. For example "OverSubscribe=FORCE:4" enables each node, socket or core to execute up to four jobs at once. Recommended only for BlueGene systems configured with small blocks or for systems running with gang scheduling (PreemptMode=suspend,gang). NOTE: PreemptType=QOS will permit one additional job to be run on the partition if started due to job preemption. For example, a configuration of OverSubscribe=FORCE:1 will only permit one job per resources normally, but a second job can be started if done so through preemption based upon QOS. The use of PreemptType=QOS and PreemptType=Suspend only applies with SelectType=cons_res.

YES

Makes all resources in the partition available for sharing upon request by the job. Resources will only be over-subscribed when explicitly requested by the user using the "--oversubscribe" option on job submission. May be followed with a colon and maximum number of jobs in running or suspended state. For example "OverSubscribe=YES:4" enables each node, socket or core to execute up to four jobs at once. Recommended only for systems running with gang scheduling (PreemptMode=suspend,gang).

NO

Selected resources are allocated to a single job. No resource will be allocated to more than one job.

Name by which the partition may be referenced (e.g. "Interactive"). This name can be specified by users when submitting jobs. If the PartitionName is "DEFAULT", the values specified with that record will apply to subsequent partition specifications unless explicitly set to other values in that partition record or replaced with a different set of default values. Each line where PartitionName is "DEFAULT" will replace or add to previous default values and not a reinitialize the default values.

Mechanism used to preempt jobs from this partition when PreemptType=preempt/partition_prio is configured. This partition specific PreemptMode configuration parameter will override the PreemptMode configuration parameter set for the cluster as a whole. The cluster-level PreemptMode must include the GANG option if PreemptMode is configured to SUSPEND for any partition. The cluster-level PreemptMode must not be OFF if PreemptMode is enabled for any partition. See the description of the cluster-level PreemptMode configuration parameter above for further information.

Jobs submitted to a partition with a higher priority tier value will be dispatched before pending jobs in partition with lower priority tier value and, if possible, they will preempt running jobs from partitions with lower priority tier values. Note that a partition's priority tier takes precedence over a job's priority. The value may not exceed 65533. Also see PriorityJobFactor.

Used to extend the limits available to a QOS on a partition. Jobs will not be associated to this QOS outside of being associated to the partition. They will still be associated to their requested QOS. By default, no QOS is used. NOTE: If a limit is set in both the Partition's QOS and the Job's QOS the Partition QOS will be honored unless the Job's QOS has the OverPartQOS flag set in which the Job's QOS will have priority.

Specifies users of this partition are required to designate a reservation when submitting a job. This option can be useful in restricting usage of a partition that may have higher priority or additional resources to be allowed only within a reservation. Possible values are "YES" and "NO". The default value is "NO".

Specifies if only user ID zero (i.e. user root) may allocate resources in this partition. User root may allocate resources for any other user, but the request must be initiated by user root. This option can be useful for a partition to be managed by some external entity (e.g. a higher-level job manager) and prevents users from directly using those resources. Possible values are "YES" and "NO". The default value is "NO".

State of partition or availability for use. Possible values are "UP", "DOWN", "DRAIN" and "INACTIVE". The default value is "UP". See also the related "Alternate" keyword.

UP

Designates that new jobs may queued on the partition, and that jobs may be allocated nodes and run from the partition.

DOWN

Designates that new jobs may be queued on the partition, but queued jobs may not be allocated nodes and run from the partition. Jobs already running on the partition continue to run. The jobs must be explicitly canceled to force their termination.

DRAIN

Designates that no new jobs may be queued on the partition (job submission requests will be denied with an error message), but jobs already queued on the partition may be allocated nodes and run. See also the "Alternate" partition specification.

INACTIVE

Designates that no new jobs may be queued on the partition, and jobs already queued may not be allocated nodes and run. See also the "Alternate" partition specification.

TRESBillingWeights is used to define the billing weights of each TRES type that will be used in calculating the usage of a job. The calculated usage is used when calculating fairshare and when enforcing the TRES billing limit on jobs.

Any TRES Type is available for billing. Note that the base unit for memory and burst buffers is megabytes.

By default the billing of TRES is calculated as the sum of all TRES types multiplied by their corresponding billing weight.

The weighted amount of a resource can be adjusted by adding a suffix of K,M,G,T or P after the billing weight. For example, a memory weight of "mem=.25" on a job allocated 8GB will be billed 2048 (8192MB *.25) units. A memory weight of "mem=.25G" on the same job will be billed 2 (8192MB * (.25/1024)) units.

When a job is allocated 1 CPU and 8 GB of memory on a partition configured with TRESBillingWeights="CPU=1.0,Mem=0.25G,GRES/gpu=2.0", the billable TRES will be: (1*1.0) + (8*0.25) + (0*2.0) = 3.0.

If PriorityFlags=MAX_TRES is configured, the billable TRES is calculated as the MAX of individual TRES' on a node (e.g. cpus, mem, gres) plus the sum of all global TRES' (e.g. licenses). Using the same example above the billable TRES will be MAX(1*1.0, 8*0.25) + (0*2.0) = 2.0.

If TRESBillingWeights is not defined then the job is billed against the total number of allocated CPUs.

NOTE: TRESBillingWeights doesn't affect job priority directly as it is currently not used for the size of the job. If you want TRES' to play a role in the job's priority then refer to the PriorityWeightTRES option.

There are a variety of prolog and epilog program options that execute with various permissions and at various times. The four options most likely to be used are: Prolog and Epilog (executed once on each compute node for each job) plus PrologSlurmctld and EpilogSlurmctld (executed once on the ControlMachine for each job).

NOTE: Standard output and error messages are normally not preserved. Explicitly write output and error messages to an appropriate location if you wish to preserve that information.

NOTE: By default the Prolog script is ONLY run on any individual node when it first sees a job step from a new allocation; it does not run the Prolog immediately when an allocation is granted. If no job steps from an allocation are run on a node, it will never run the Prolog for that allocation. This Prolog behaviour can be changed by the PrologFlags parameter. The Epilog, on the other hand, always runs on every node of an allocation when the allocation is released.

If the Epilog fails (returns a non-zero exit code), this will result in the node being set to a DRAIN state. If the EpilogSlurmctld fails (returns a non-zero exit code), this will only be logged. If the Prolog fails (returns a non-zero exit code), this will result in the node being set to a DRAIN state and the job being requeued in a held state unless nohold_on_prolog_fail is configured in SchedulerParameters. If the PrologSlurmctld fails (returns a non-zero exit code), this will result in the job requeued to executed on another node if possible. Only batch jobs can be requeued. Interactive jobs (salloc and srun) will be cancelled if the PrologSlurmctld fails.

Information about the job is passed to the script using environment variables. Unless otherwise specified, these environment variables are available to all of the programs.

If this job is part of a job array, this will be set to the job ID. Otherwise it will not be set. To reference this specific task of a job array, combine SLURM_ARRAY_JOB_ID with SLURM_ARRAY_TASK_ID (e.g. "scontrol update ${SLURM_ARRAY_JOB_ID}_{$SLURM_ARRAY_TASK_ID} ..."); Available in PrologSlurmctld and EpilogSlurmctld only.

If this job is part of a job array, this will be set to the task ID. Otherwise it will not be set. To reference this specific task of a job array, combine SLURM_ARRAY_JOB_ID with SLURM_ARRAY_TASK_ID (e.g. "scontrol update ${SLURM_ARRAY_JOB_ID}_{$SLURM_ARRAY_TASK_ID} ..."); Available in PrologSlurmctld and EpilogSlurmctld only.

The exit code of the job script (or salloc). The value has the format <exit>:<sig>. The first number is the exit code, typically as set by the exit() function. The second number of the signal that caused the process to terminate if it was terminated by a signal. Available in EpilogSlurmctld only.

Slurm is able to optimize job allocations to minimize network contention. Special Slurm logic is used to optimize allocations on systems with a three-dimensional interconnect (BlueGene, etc.) and information about configuring those systems are available on web pages available here: <https://slurm.schedmd.com/>. For a hierarchical network, Slurm needs to have detailed information about how nodes are configured on the network switches.

Given network topology information, Slurm allocates all of a job's resources onto a single leaf of the network (if possible) using a best-fit algorithm. Otherwise it will allocate a job's resources onto multiple leaf switches so as to minimize the use of higher-level switches. The TopologyPlugin parameter controls which plugin is used to collect network topology information. The only values presently supported are "topology/3d_torus" (default for IBM BlueGene and Cray XT/XE systems, performs best-fit logic over three-dimensional topology), "topology/none" (default for other systems, best-fit logic over one-dimensional topology), "topology/tree" (determine the network topology based upon information contained in a topology.conf file, see "man topology.conf" for more information). Future plugins may gather topology information directly from the network. The topology information is optional. If not provided, Slurm will perform a best-fit algorithm assuming the nodes are in a one-dimensional array as configured and the communications cost is related to the node distance in this array.

If the cluster's computers used for the primary or backup controller will be out of service for an extended period of time, it may be desirable to relocate them. In order to do so, follow this procedure:

There should be no loss of any running or pending jobs. Ensure that any nodes added to the cluster have the current slurm.conf file installed.

CAUTION: If two nodes are simultaneously configured as the primary controller (two nodes on which ControlMachine specify the local host and the slurmctld daemon is executing on each), system behavior will be destructive. If a compute node has an incorrect ControlMachine or BackupController parameter, that node may be rendered unusable, but no other harm will result.

The "include" key word can be used with modifiers within the specified pathname. These modifiers would be replaced with cluster name or other information depending on which modifier is specified. If the included file is not an absolute path name (i.e. it does not start with a slash), it will searched for in the same directory as the slurm.conf file.

There are three classes of files: Files used by slurmctld must be accessible by user SlurmUser and accessible by the primary and backup control machines. Files used by slurmd must be accessible by user root and accessible from every compute node. A few files need to be accessible by normal users on all login and compute nodes. While many files and directories are listed below, most of them will not be used with most configurations.

If this specifies a file, it must be writable by user SlurmUser. The file must be accessible by the primary and backup control machines. It is recommended that the file be readable by all users from login and compute nodes.

Note that while Slurm daemons create log files and other files as needed, it treats the lack of parent directories as a fatal error. This prevents the daemons from running if critical file systems are not mounted and will minimize the risk of cold-starting (starting without preserving jobs).

Log files and job accounting files, may need to be created/owned by the "SlurmUser" uid to be successfully accessed. Use the "chown" and "chmod" commands to set the ownership and permissions appropriately. See the section File and Directory Permissions for information about the various files and directories used by Slurm.

It is recommended that the logrotate utility be used to ensure that various log files do not become too large. This also applies to text files used for accounting, process tracking, and the slurmdbd log if they are used.

Here is a sample logrotate configuration. Make appropriate site modifications and save as /etc/logrotate.d/slurm on all nodes. See the logrotate man page for more details.

Copyright (C) 2002-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).Copyright (C) 2008-2010 Lawrence Livermore National Security.Copyright (C) 2010-2017 SchedMD LLC.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.